Tahm Kench the River King

Devour 2 (As this enters the battlefield, you may sacrifice any number of creatures. This creature enters the battlefield with double that many +1/+1 counters on it.)
Phasing, Menace
When Tahm Kench the River King deals combat damage to an opponent, that opponent gains a piranha counter. If 4 piranha counters are on said opponent at the start of their turn, that opponent loses the game.