Gryrro, Inquisitive Dragonling

Familiar (Starts outside the game face up. Can't be
cast. If it would leave the battlefield, exile it instead.)
Flying, haste
When Gryrro attacks, put a +1/+1 counter on
Gryrro and then, if it has five or more counters
on it, exile Gryrro and put Gryrro, Lord of the
Skies you own from outside the game onto the
battlefield tapped and attacking under your
control.