Your search for "regeneration 506" revealed the following:
Regeneration (LEB) from Limited Edition Beta, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: Quinton Hoover Card Text:G: Target creature regenerates.
Regeneration (ICE) from Ice Age, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: Justin Hampton Card Text:When Regeneration comes into play, choose target creature.G: Regenerate creature Regeneration enchants.
Regeneration - Retro Frame (30A) from 30th Anniversary Edition, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: Quinton Hoover Card Text:This version of this card has a non-standard Magic back. It is not legal for constructed play.Enchant creatureG:...
Regeneration (LEA) from Limited Edition Alpha, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: Quinton Hoover Card Text:G: Target creature regenerates.
Regeneration (CEI) from Intl. Collectors’ Edition, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: Quinton Hoover Card Text:(This card has square corners and a gold bordered back. Not tournament legal.)G: Target creature regenerates.