Infestor

Burrow (This unit can become unable to block, attacked, or be attacked or vice versa instead of attacking.)
{p/b}: Gain control of target unit an opponent controls with total cost of 3 or less. You may only control 1 unit at a time this way. They regains the unit if the infester dies or you dismiss it.
"Even if you survive, you will never live it down."
- A Dominion marine