Bess, Soul Nourisher (NCC 67)

Legendary Creature — Human Citizen • Mana cost: {1}{G}{W} • New Capenna Commander • Rare

Whenever one or more other creatures you control with base power and toughness 1/1 enter, put a +1/+1 counter on Bess.
Whenever Bess attacks, each other creature you control with base power and toughness 1/1 gets +X/+X until end of turn, where X is the number of +1/+1 counters on Bess.

Illustrated by Leonardo Santanna.