Today we have the Portuguese ‘Pikachu around the World’ part. I will add the same quote again, which I’ll do for all parts:
The first nine parts were Chinese (click here to go to that part); Dutch (click here to go to that part); English (click here to go to that part); French (click here to go to that part); German (click here to go to that part); Italian (click here to go to that part); Japanese (click here to go to that part); Korean (click here to go to that part); and Polish (click here to go to that part).
The Portuguese portion of my Pikachu collection is 100% complete, mainly because of an amazing Brazilian middleman I met in 2017, who helped me go from 30% on both my Pikachu and Seviper collections, to 100% Seviper and 99% Pikachu, and has helped me with every new Portuguese release since. 
Portuguese:
Let me start with a picture of all Portuguese Pikachu cards in my collection:
Unfortunately, I haven’t been able to find any source for Portuguese release dates. If anyone knows any source at all with Portuguese release months + years, I would greatly appreciated it!
Anyway, Portuguese cards are released in both Portugal and Brazil. During the WotC era, the Portuguese cards from Portugal were printed in the WotC facility in Belgium, like all other European language cards. The Portuguese cards from Brazil were printed by the distributing company Copag in Brazil itself. After the WotC era, only Copag continued to print Portuguese cards, which are imported to Portugal by the distributer Devir, which still holds true to this day with the current Sword & Shields era sets. From what I’ve heard, almost all collectors from Portugal prefer English cards over Portuguese cards though, hence the lack of any useful online sources… 
The Portuguese sets are a bit of an odd one, kinda like Korean. Its sets and promos are sprinkled in all the eras and appear pretty random until we’ve reached the XY era of sets.
The first Portuguese set, released somewhere at the start/mid 2000, is of course the Base Set, with both a 1st and unlimited edition Pikachu.
After that came the Portuguese Jungle set, released mid/late 2000, with a 1st and unlimited edition Pikachu again.
The only Portugese WotC era Pikachu promo is the #1 Ivy Pikachu promo with golden Pikachu tail stamp, from the Pikachu World Collection 2000, which we’ve mentioned a bunch of times in the other parts. The nine cards in this collection were released at the Summer Olympics in Sydney, Australia between September 13th and October 1st, 2000.
And the final WotC era Portuguese set was the Fossil set, released near the end of 2000 (I assume), lacking any Pikachu cards.
After that the first Portuguese set of the EX era, EX Ruby & Sapphire, was released somewhere in 2004. This set lacked any Pikachu cards.
Next we surprisingly enough have the Portuguese EX Team Rocket Returns set, which was released in Japanese, English, and Portuguese, but none of the other languages. This Portuguese set was probably released somewhere near the start of 2005, and also didn’t contained any Pikachu cards.
Next we have the EX Deoxys set, probably released mid 2005. This set also lacked any Pikachu cards. (This set was pretty short-printed in Portuguese. In fact, I’ve only very recently learned this set was released in Portuguese in the first place.)
After that we have the Portuguese EX Emerald set, probably also released mid 2005, containing a Pikachu Reverse Holofoil and all three non-Holo EX era codes.
Next we have the first two of twelve Portuguese Half Decks, released in September 2005 in Brazil and October 2005 in Portugal: Mudkip Picture Book and Torchic Picture Book. The first four Half Decks were also released in Spanish, and the other eight were exclusively released in Portuguese. None of these decks contained any new cards however. These first two Half Decks contained cards from the earlier mentioned Portuguese EX Ruby & Sapphire set.
Near the end of 2005 the next two Portuguese Half Decks were released in Brazil: Treecko Picture Book and Ralts Picture Book. These Portuguese Half Decks were later in April 2006 also released in Portugal. Just like the first two Portuguese/Spanish exclusive Half Decks, these two Half Decks contained cards from the EX Ruby & Sapphire set.
After that we had the Portuguese POP Series 2 mini set, which I assume is released near the end of 2005. This mini set did contain a Pikachu card.
After that came the Portuguese EX Unseen Forces set, released somewhere near the start of 2006 and lacking any Pikachu cards.
Released near the start of 2006 as well was the Portuguese POP Series 3, also lacking any Pikachu cards.
Next we had some more of the Portuguese exclusive Half Decks:
- Exploud Picture Book was released in March 2006 and Rayquaza Picture Book was released in April 2006, both containing Portuguese EX Emerald cards;
- Ho-Oh Picture Book was released in May 2006 and Lugia Picture Book was released in June 2006, both containing Portuguese EX Unseen Forces cards.
After that we had the Portuguese EX Legend Maker set, released somewhere mid 2006. The Secret Rare box topper Pikachu of this set wasn’t released in Portuguese, so for that reason this Portuguese set also lacked any Pikachu cards.
Near the end of 2006 the last four Portuguese exclusive Half Decks were released, all four containing cards from the Portuguese EX Legend Maker set: Golem Picture Book; Omastar Picture Book; Machamp Picture Book; and Gengar Picture Book.
The POP Series 4 was also released in Portuguese, probably somewhere in 2006 as well. This mini set did include a Pikachu card.
Next we have the Diamond & Pearl era, of which the first set by the same name was released in Portuguese somewhere in 2007. From the DP era onward for a couple of eras, all Portuguese sets didn’t contained any Reverse Holos anymore. This set also lacked any Pikachu cards.
The next DP era set Mysterious Treasures was released in Portuguese as well, somewhere in 2008. This set did contain a Pikachu card.
Then we had the Portuguese Secret Wonders set, also released somewhere in 2008. This set lacked both Pikachu cards and Reverse Holos.
Next it’s quiet again with Portuguese set releases, but we did have the two Portuguese Pikachu cards from the Pikachu World Collection 2010, of which the Japanese version was released on July 8th, 2010 and the English one in November 2010, as mentioned a few times before in earlier parts.
The next Portuguese set release was in the Heart & Gold era, with the set by the same name being released somewhere near the start of 2011. This set also included a Pikachu card, but again only in non-Holo since this entire era didn’t had any Portuguese Reverse Holos either.
The second HSS era set Unleashed was released in Portuguese as well, released somewhere in 2011. This set didn’t contained any Pikachu cards.
Next we skip to the Black & White era, for which the first set by the same name was released in Portuguese somewhere near the end of 2011. This set also contained a Secret Rare Pikachu card.
Next is the Portuguese Noble Victories from somewhere in 2012, which didn’t contain any Pikachu card.
The next Portuguese BW era set was Next Destinies from somewhere in 2012, which did contain a non-Holo Pikachu again. The Portuguese sets for the BW era still didn’t contained any Reverse Holos.
Then we had the Portuguese Dragons Exalted set, released somewhere in either 2012 or 2013, which also lacked any Pikachu cards.
The next Portuguese BW era set was Boundaries Crossed, released somewhere in 2013, which did contain a Pikachu card.
Next we have the Portuguese Plasma Storm set, released somewhere in 2013. As well as the Portuguese Plasma Blast set, released somewhere near the end of 2013. Both of these Portuguese BW era sets lacked any Pikachu cards.
Next we have the XY era, at which point the Portuguese releases became more active and consistent (although this entire era still didn’t contained any Portuguese Reverse Holos either). The Portuguese sets were usually released 2-6 weeks after its English release, so we’ll use that information for an estimation of the release months from this point onward.
We start with the Portuguese XY set from February/March 2014, which contained a Pikachu card.
Next we have the Portuguese Flashfire set, released in May/June 2014. This set didn’t contained any Pikachu cards.
Released in August/September 2014 is the Portuguese Furious Fists set, which did contain a Pikachu.
In November/December 2014 we had the Portuguese Phantom Forces set. This set lacked any Pikachu cards, though.
Next in February/March 2015 was the Portuguese Primal Clash set, also without any Pikachu cards.
The same applied to the smaller Portuguese Double Crisis mini set from March/April/May 2015.
The Portuguese Roaring Skies set set from May/June 2015 did contain a Pikachu card however.
Next we have the Ancient Origins set, also lacking any Pikachu cards and released in August/September 2015.
And the final Portuguese set from 2015 is BREAKthrough, released in November/December 2015, which did contain a Pikachu card.
Also released in November/December 2015 is the Portuguese XY84 Pikachu EX promo, which just like the other languages came in Pikachu EX Legendary Collection boxes.
Next in February/March 2016 we have the Portuguese BREAKpoint set, lacking any Pikachu cards.
Also released in February 2016 was the Holofoil XY95 Pikachu promo. Thanks to Bulbapedia, I can at least give some release information about this Brazilian exclusive Portuguese card. The earlier mentioned distributer Copag organized events at select stores in Brazil. Each store received 55 copies of this XY95 Pikachu promo; 3 Badge cases; 3 bags with Play! Pokémon logo; and 12 Mewtwo deck boxes. Exclusive merchandise was also available at these tournaments. Later on, this Pikachu promo was also given to customers at RiHappy, PB Kids, BMart, and Planeta Bringuedos stores on February 27th and 28th, 2016 (20th Pokémon Day), when they bought at least two Pokémon TCG products - excluding loose booster packs (which are only ~1 USD each in Brazil and contain just five cards).
The Portuguese Generations set did contain both a non-Holo and Full Art Pikachu card, released somewhere in February/March/April 2016.
Next we have the Portuguese Fates Collide set from May/June 2016, lacking any Pikachu cards.
The XY Trainer Kit: Pikachu Libre & Suicune was released in Portuguese as well in May/June 2016, which of course contains both a non-Holo and Holofoil Pikachu Libre card.
And the final Portuguese XY era set that was released was Steam Siege, released in August/September 2016, also without any Pikachu cards.
Another XY era Pikachu promo from 2016 was the XY124 Full Art Pikachu EX, released inside the Pikachu EX Red & Blue Collection box in September/October 2016. This card wasn’t released as a Jumbo, unlike the same card that came from European releases.
And the final Portuguese XY Pikachu EX promo was the XY174 Pikachu EX which came in the Pikachu Battle Heart Tins in September/October/November 2016 as well.
Next we have the Sun & Moon era, at which point Portuguese Reverse Holos finally returned.
The first Portuguese Sun & Moon era set is the set by the same name is released in February/March 2017, which didn’t contained any Pikachu cards.
In April/May/June 2017 we also had the SM Trainer Kit: Lycanroc & Alolan Raichu, of which the Alolan Raichu Half Deck contained two differently numbered Pikachu cards with the same artwork.
Next we have the Portuguese Guardians Rising set from May/June 2017, also lacking any Pikachu cards.
Followed by the Portuguese Burning Shadows set from August/September 2017, which did have a Pikachu in it, both as non-Holo and Reverse Holo.
Next in October/November 2017 we had the Portuguese Shining Legends set, which again contained Pikachu cards.
The Let’s Play, Pikachu! Theme Deck from May/June 2017 containing a Shattered Holofoil version of this Pikachu artwork was released in Portuguese as well.
And Brazil also had their first and thus far only McDonald’s Collection set with a McDonald’s Holofoil Pikachu, released near the end of 2019.
In October/November 2017 we also had the Portuguese Shining Legends Pikachu Pin Collection accompanying the Shining Legends set, containing the Holofoil SM76 Pikachu promo.
The same applied to the Portuguese Shining Legends Super-Premium Collection box, containing the Holofoil SM81 Pikachu promo.
On November 5th, 2017 (thanks imdb) we also had the non-Holo SM108 Ash’s Pikachu promo, given as part of the 20th Pokémon movie: I Choose You! cinematic release.
Then we had the Portuguese Crimson Invasion set from November/December 2017, with again both a non-Holo and Reverse Holo Pikachu.
Followed by the Portuguese Ultra Prism set of February/March 2018, without Pikachu cards.
The same applies to the next few Portuguese set again:
- Forbidden Light from May/June 2018;
- Celestial Storm from August/September 2018;
- Lost Thunder from November/December 2018.
In November/December 2018 we had the Holofoil SM157 Pikachu promo (with a nice swirl on my copy 
), released inside the Portuguese Pikachu & Eevee Pokéball Collection box.
The first Portuguese set from 2019 (February/March 2019 to be … well not exact, lol 
) is the Teams Up set, containing two Ultra and a Hyper Secret Rare Pikachu & Zekrom GX.
In March/April 2019 we also had the SM168 Pikachu & Zekrom GX Full Art promo, released inside the Portuguese Tag Team Tin.
In March/April/May 2019 we also had the Portuguese Detective Pikachu mini set, which as its name suggests contained a Holofoil Detective Pikachu card.
Then we had the Portuguese Unbroken Bonds set in May/June 2019, which again contained a non-Holo and Reverse Holo Pikachu.
On May 9th, 2019 (thanks again imdb) we also had the Portuguese Holofoil SM190 Detective Pikachu promo, released to celebrate the cinematic release of the Detective Pikachu movie.
Followed by the Portuguese Unified Minds set, released somewhere in August/September 2019. This set contained not one, but two Pikachu cards.
Then the Hidden Fates set from August/September/October 2019, which also contained a Pikachu.
The final Portuguese set of the SM era was Cosmic Eclipse from November/December 2019, which contained both a regular and Character Ultra Rare Pikachu.
And in November/December 2019 we also had the release of the Portuguese Pikachu GX & Eevee GX Special Collection box, containing the SM232 Full Art Pikachu GX promo in both regular and Jumbo size (the first Portuguese Jumbo Pikachu card), as well as the Holofoil SM234 Pikachu promo and two Eevee promos.
Next we have the current Sword & Shield era, starting with the set by the same name in February/March 2020, which contained a Pikachu card.
Next we have two Portuguese Sword & Shield era sets lacking Pikachu cards:
- Rebel Clash in May/June 2020;
- Darkness Ablaze in August/September 2020.
In August/September 2020 accompanying the Darkness Ablaze set we also had the Darkness Ablaze Blisters, including one containing the Holofoil SWSH039 Pikachu promo.
In September/October 2020 there were the Portuguese V Power Tins, including a Full Art Pikachu V promo with number SWSH063.
Followed by a personal favorite set (not!.. 
) of mine, the Portuguese Vivid Voltage from November/December 2020, containing three Pikachu V/Vmax Ultra Rares and a Hyper Secret Rare Pikachu Vmax.
And the final Portuguese Sword & Shield era set released before February 27th, 2021 (probably?) is Shining Fates, lacking any Pikachu cards.
But of course we have one more Portuguese Pikachu card released slightly after this boundary date for my collection goals in March/April 2021, which is the Jumbo Base Set reprint for the 25th anniversary. Unlike this same Base Set Pikachu Jumbo reprint in other languages, the 25th anniversary logo is always non-Holo on this Portuguese card.
And there you have it, all Portuguese Pikachu cards and set releases (despite not knowing the release dates for any of the sets 
). And again, huge thanks to my Brazilian middleman Francis, since without him I might not have all Portuguese Pikachu (and Seviper) cards by now.
Greetz,
Quuador