Garfield and Odie, Best Buds - 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 deals damage to any target equal to the number of Dogs you control. You gain life equal to the number of Cats you control.