Anton, the Lost Mentor

Whenever a Squirrel enters the battlefield under
your control put a -1/-1 counter on Anton, the
Lost Mentor and choose one:
• Anton, the Lost Mentor deals 2 damage to any
target
• Another target creature gets +2/+2
If Anton, the Lost Mentor would be put into
your graveyard because of -1/-1 counters, return
him to the battlefield with no counters and
destroy all Squirrels.