A10 Warthog

Flying, Haste

Whenever A10 attacks, it gets +X/+0 until end
of turn, where X is the greatest mana value
among artifacts you control.

Whenever you expend 6, gain control of up to one target artifact for as long as you control A10. (You expend 6 as you spend your sixth total mana to cast spells during a turn.)
(Pyreswipe Hawk)