Karrthus' Egg

Shroud
{x}: Put X decade marks on Karrthus' Egg.
If there are 30 or more decade marks on
Karrthus' Egg, you may sacrifice it. If you do, put
a 12/12 legendary red Dragon creature token with
flying, haste, trample and protection from blue
named:"Sister of Karrthus" onto the battlefield
under your control.