"But Mommy said!" --Grub to his brother, Trouble, in Artemis Fowl Grub Kelp is Trouble Kelp's little brother and a corporal in LEPrecon. The two brothers are polar opposites. Corporal Kelp will often complain about the most trivial things, such as getting a hangnail or his boots getting scuffed on a protuding floor tile. He often refers to the Kelp brothers' "Mommy" and calls his big brother 'Trouble' 'Trub' or 'Trubs'. He believes it is "Trub's" job to protect him on missions together, and often freaks out in trouble situations. He has a very exaggerated sense of self.