Dragonslayer Bolbi the Great

Offspring {2} (You may pay an additional
{2} as you cast this spell. If you do, when this
creature enters, create a 1/1 token copy of it.)
Whenever you attack, choose one —
• Create a 1/1 white Rabbit creature token
that's tapped and attacking.
• Attacking creatures you control get +1/+1
until end of turn.