Dave, The Octopus

Enrage: Whenever a creature deals damage to Dave, The Octopus put a plot counter on each creature that shares types with it.
At the beginning of your end step if their is five or more plot counters on a creature it becomes a 2/1 horror with "at the beginning of your upkeep you lose two life". Put a plot counter on each creature with a plot counter that isn't a horror.
{t}:{g} create a 3/3 green octopus.