A creature with this condition marker has been impregnated with an Ichthellid Larva. Ichthellid Larva is a poison condition with a removal cost of 5. The Ichthellid Larva marker is controlled by the controller of the Ichthellid that placed the maker. A creature can have only one Ichthellid Larva marker on it. When this creature is destroyed, the controller of the Ichthellid Larva marker may choose an Ichthellid creature from his spellbook or discard pile, and place it face down in the zone the creature was in when it was destroyed. This Ichthellid comes into play at the end of teh round for no mana cost, similar to how the Reanimate effect works.
Ichthellid Larva (Condition Marker)
Now, given that the only thing you have to do is damage a living creature and it not be destroyed, I think this creature has a great chance a multiplying. The biggest problem will be this creature has 5 life and 2 armor, which will not survive more than 1 or 2 attacks on average. Considering all of this I still believe the Ichthellid is a good choice for the Necromancer or the Warlock.