Michelangelo, Mutant BFF (TMT-120) - Teenage Mutant Ninja Turtles

Each creature you control with a counter on it can’t be blocked by more than one creature.

Whenever Michelangelo enters or attacks, 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.”)