Grimgwinnn, Squirrel-Born

Grimgwinnn, Squirrel-Born enters the battlefield tapped and doesn't untap during your untap step.
Sacrifice another squirrel: Untap Grimgwinnn
and put a +1/+1 counter on it.
Whenever Grimgwinnn attacks, destroy target Bidoof defending player controls, then put a +1/+1 counter on Grimwinnn.