The Prism Swarm

When you cast a spell, put a +1/+1 counter on The Prism Swarm.
{w}{u}{b}{r}{g}, Remove five +1/+1 counters off of The Prism Swarm: Search for three artifacts and put them on the battlefield.
They are voracious devourers of spells. The residue can feed them for a week.- Laboratory Notes.