Alias
The Monster from Planet X; His Divine Majesty King Groot the 23rd, Monarch of Planet X, custodian of the branch worlds, ruler of all the shades, Flora colossus Information-silk
  
J'Onn J'Onzz, Big Green Buddy, J.J., Jolly Green Giant, Light to the Light, Manhunter, Manhunter from Mars, Son of Mars, Bronze Wraith, Bloodwynd, many others