Rakdos Guildmage [Champs and States] Cold Foil - Golden Whenever a Dragon you control

Whenever a Dragon you control is dealt damage

Set: Commander Anthology Type: Legendary Creature — Elf Warrior Rarity: Rare Cost: {1}{G}{G} {G}: Regenerate another target Elf

Set: Kamigawa: Neon Dynasty Type: Legendary Creature — Fox Advisor Rarity: Rare Cost: {1}{W} Whenever an Aura enters the battlefield under your control

but not many

It is discovery

Rakdos Guildmage [Champs and States] Cold Foil - Golden Whenever a Dragon you controlSet: Champs and States Type: Creature Zombie Shaman Rarity: Rare Cost: {B R}{B R} ({B R} can be paid with either {B} or {R}.) {3}{B}, Discard a card: Target creature gets 2 2 until end of turn. {3}{R}: Create a 2 1 red Goblin creature token with haste. Exile it at the beginning of the next end step.