Ramos, Contagion Engine

Flying
Whenever you cats a spell, put a +1/+1 counter on Ramos, then target player loses 1 life for each +1/+1 counter on Ramos.
{x}{w/b}{w/b}{w/b}, {t}, Remove X +1/+1 counters from Ramos: Add X mana in any combination of {w} or {b} to your mana pool.