Jir'ta, Bakk'ur Primal

Jir'ta, Bakk'ur Primal can be cast for no cost from
anywhere if your opponent looks through their
own library in any way. When Jir'ta enter's the
battlefield and on every upkeep, flip a coin. If
heads, roll a d6. If 6, roll again and add the
results until a 6 is not rolled. If 1, exile
Jir'ta, Bakk'ur Primal.
Jir'ta, Bakk'ur Primal's Power and toughness are
equal to the total result.