Acnologia, First Dragon Slayer

Deathtouch
Virus-(When this creature deals combat damage to a player put a virus counter on a creature they control or them when the virus counters are equal to the creatures converted mana cost it becomes a zombie and can't block or attack if a player has 3 or more zombies on their field they lose 5 life, if a player has 15 virus counters on them they lose the game)