What is the name of the man who lives at Gatsby's mansion and uses his pool?

The man who lives at Gatsby’s mansion and uses its pool is Ewing Klipspringer. He is one of the many casual hangers-on attracted to Jay Gatsby’s lavish West Egg parties, and he appears to treat the mansion almost like a convenient hotel.

Klipspringer’s presence reveals an important side of Gatsby’s social world. Huge crowds attend the parties, but most guests barely know their host and disappear when the entertainment ends. Klipspringer goes further: he remains in the house after Gatsby’s death, illustrating how Gatsby’s wealth has attracted dependents rather than loyal friends.

Readers sometimes confuse Klipspringer with James Gatz, Gatsby’s birth name, or with Dan Cody, the wealthy adventurer who influenced Gatsby’s youth. Neither man is the resident who uses the pool. Klipspringer is also notably absent from Gatsby’s funeral, despite having benefited from the mansion’s hospitality. The detail helps Fitzgerald contrast superficial social connections with genuine friendship.