Tik-Tok, the Ticking Clock

Haste, Trample, Lifelink, Flying
When Tik-Tok enters the battlefield pay X life.
Put a tenth X time counters on Tik-Tok.
At the beginning of your upkeep remove a time counter from Tik-Tok.
If Tik-Tok has no time counters on it you lose
the game.