Fynn, the Fangbearer (SLD-1449) - Secret Lair Drop / Westley, Dread Pirate Roberts (Borderless)

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever a creature you control with deathtouch deals combat damage to a player, that player gets two poison counters. (A player with ten or more poison counters loses the game.)