Crakex, Venomous Libitus

Menace, hexproof, deathtouch
Whenever Crakex enters the battlefield, create a
2/4 white ox creature token. At the beginning of
your upkeep, create a 2/4 white ox creature
token. Oxen in play has (During each players end phase, that player may pay {p/b}{p/b} or discard a
card.)
If Crakex attacks or blocks, it loses hexproof until
the end of turn.