Eustace Blint is the great-nephew of "Gramps" Gorbuckle, though the identity of the intervening generation isn't necessarily clear. He works as a gardener, taking advantage of his ability to produce various liquids from his vase-shaped head. In his gardening duties, he generally produces water for the plants and poison for weeds.
Eustace also has a sort of a one-sided friendship with plumber Ptolemy Brown, one-sided in that while Eustace seems to have a genuine fondness and loyalty toward Ptolemy the latter seems just out to take advantage of Eustace. Still, Ptolemy often ropes Eustace into his schemes, or at least gets him to temporarily stand in for a fountain under repair.