Yeller, loyal to the end

Vanishing 3 (This creature enters the battlefield with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
You can't lose the game.
"No, Mama!" "There's no hope for him now, Travis. He's suffering. You know we've got to do it." "Yes, Mama. But he was my dog... I'll do it."