Rakdos firebug

Hexproof
{x}{x}{x}: Monstrosity X (If this permanent isn't monstrous,
put X +1/+1 counters on it and it becomes monstrous.)
{b}{b}{r}{r}:feed. (you may have this creature fight
target creature you control. if the other creature dies,
put X +1/+1 counters on Rakdos firebug,
where X is that creatures power.)