Genghis Frog (Teenage Mutant Ninja Turtles)

Legendary Creature Ñ Frog Mutant Rogue - Trample
Whenever Genghis Frog or another Mutant you control enters, 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.")