Doc Ock's Tentacles
Artifact — Equipment
Oracle Text
Whenever a creature you control with mana value 5 or greater enters, you may attach this Equipment to it.
Equipped creature gets +4/+4.
Equip 
Flavor Text
Once powerful tools of science, Dr. Otto Octavius's mechanical arms became his most formidable weapons.
Rarity
in its mana cost, X is 0 when determining its mana value.