Tavros, Pupa Pan

Whenever one or more other creatures with
base power and toughness 1/1 enter the
battlefield under your control, put a +1/+1
counter on Tavros.
Whenever Tavros 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 Tavros.