I think this one is more well-known, but still worth something to share here imo. The Ruin Wall card from the Japanese Crossing the Ruins… set (Neo Discovery in English) has two different artwork versions:
Kabuto (with Raichu shadow) and Aerodactyl (with Pikachu shadow):
(The English set only contains the artwork with the Kabuto.) I guess the one with the Aerodactyl and Pikachu shadow is also one for your non-Pikachu cards featuring Pikachu thread, @sacari . 
Greetz,
Quuador