Your search for "equestrian skill 204" revealed the following:
Equestrian Skill (SOI) from Shadows over Innistrad, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: Zoltan Boros Card Text:Enchant creatureEnchanted creature gets +3/+3.As long as enchanted creature is a Human, it has trample.
Equestrian Skill (Foil) (SOI) from Shadows over Innistrad, available at 401 Games Canada. Rarity: Common Finish: Foil Artist: Zoltan Boros Card Text:Enchant creatureEnchanted creature gets +3/+3.As long as enchanted creature is a Human, it has trample.