Wen Deryn, Heir to Marwyn

Venerate 3(As this is cast, you may tap 3 other creatures you control that shares a creature type.)
Wen Deryn's power is equal to the number
of green creatures you control.
When Wen Deryn enters the battlefield, if venerated, add {g}{g}{g}{g}. Spend this only to
cast creature spells.