Rin and Seri, Inseparable

Whenever you cast a Dog spell, create a 1/1 green Cat creature token.

Whenever you cast a Cat Spell, create a 1/1 white Dog creature token.

{r}{g}{w}, {t}: Rin and Seri, Inseparable deals damage to any target equal to the number of Dogs you control. You gain life equal to the number of cats you control.