Zagrus, Slagmouth Beast

If you sacrifice a non-beast creature as you cast
Zagrus, it costs {3} less to cast.
{5}{w}: Beasts you control gain a +1/+1 counter.
{4}{r}: Zagrus deals damage to a target equal to
the number of beasts you control.
{3}{g}: Beasts you control gain a trample counter.
{w}{r}{g}: Look at the top card of your deck if it is
a beast or a land card you may play that card for {w}{r}{g} less.