Sabertooth Cobra

Whenever Sabertooth Cobra deals damage to a player, that player gets a poison counter. The player gets another poison counter at the beginning of their next upkeep unless they pay {2} before that step. (A player with ten or more poison counters loses the game.)

The List

Mirage

If Sabertooth Cobra damages a player, he or she gets a poison counter. During that player's next upkeep, he or she gets another poison counter unless he or she pays o2 before then to prevent this effect. If any player has ten or more poison counters, he or she loses the game.

The ability still gives a poison counter even if Sabertooth Cobra leaves the battlefield before the next upkeep.