The Rollercrusher Ride (0155) [Duskmourn: House of Horror Promos]

Cost: X 2 R Delirium — If a source you control would deal noncombat damage to a permanent or player while there are four or more card types among cards in your graveyard, it deals double that damage instead.
When The Rollercrusher Ride enters, it deals X damage to each of up to X target creatures.