Horsefeathers, another way

Whenever a creature enters, you may add an amount of equal to the number of creatures you control that share a creature type with it.

: Put a charge counter on this artifact. Remove a charge counter from this artifact: Add one mana of any color.

At the beginning of your upkeep, sacrifice this enchantment unless you sacrifice a Pegasus. : Create a 1/1 white Pegasus creature token with flying.