Shriekhydra

Cast this spell for {g}{g}{g}{g} less if you have four or more card types in your graveyard.
When Shriekhydra dies, put four 4/4 green hydra tokens onto the battlefield with "when this creature dies, put four 2/2 green hydra tokens onto the battlefield with 'When this creature dies, put four 1/1 green snake tokens onto the battlefield.'"