Council of Monsters

When Council of Monsters enters the battlefield,
pick a creature type.
Creatures of that creature type have,
{x}: Monstrosity X. (If this creature isn't
monstrous, put x +1/+1 counters on it and
becomes monstrous.)
Whenever a creature you control becomes
monstrous, put x copies of that creature onto the battlefield, except they are not monstrous.