Goblin, Lizard, and Orc spells you cast costs {B}{R}{G} less to cast, this only counts for the amount of colored mana you pay.

When Oth, Hungry for Battle enters the battlfield, put a +1/+1 counter on it for each creature exiled with a snack counter.

{t}: Exile another creature you control and put a snack counter on it, put a +1/+1 counter on Oth, Hungry for Battle.