Putrefax

{3}{G}{G}Creature — Phyrexian Horror5/3

Trample, haste

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

At the beginning of the end step, sacrifice this creature.

Haste. This creature can attack and use tap abilities as soon as it comes under your control. · CR 702.10

Trample. Excess combat damage beyond what's lethal to blockers can be assigned to the player or planeswalker it's attacking. · CR 702.19

Infect. This deals damage to creatures as -1/-1 counters and to players as poison counters. (10 poison = that player loses.) · CR 702.90

Infect’s effect applies to any damage, not just combat damage. (2011-01-01)
If damage from a source with infect that would be dealt to a player is prevented, that player doesn’t get poison counters. If damage from a source with infect that would be dealt to a creature is prevented, that creature doesn’t get -1/-1 counters. (2011-01-01)
Damage from a source with infect affects planeswalkers normally. (2011-01-01)
A player who has ten or more poison counters loses the game. This is a state-based action. (2011-01-01)
The -1/-1 counters remain on the creature indefinitely. They’re not removed if the creature regenerates or the turn ends. (2011-01-01)
Damage from a source with infect is damage in all respects. If the source with infect also has lifelink, damage dealt by that source also causes its controller to gain that much life. Damage from a source with infect can be prevented or redirected. Abilities that trigger on damage being dealt will trigger if a source with infect deals damage, if appropriate. (2011-01-01)