Mitr-Gang Leader

Idle {4}{g}{w} (If you cast this card for its idle cost, it's
an Equipment spell that enters the battlefield attached
to a creature of your choice. It becomes a creature
again if not attached to a creature.)
Whenever Mitr-Gang Leader or equipped
creature attacks, put a +1/+1 counter on target creature you control.
Equipped creature gets +3/+3.