April O'Neil, Human Element

Teenage Mutant Ninja Turtles Eternal (TMC) #107 · rare

Legendary Creature — Human Detective

Whenever a player casts an artifact, instant, or sorcery spell, you create a Mutagen token. (It's an artifact with "{1}, {T}, Sacrifice this token: Put a +1/+1 counter on target creature. Activate only as a sorcery.")