Warburg was generally known by colleagues and friends as "Heff", partly in punning references to his initlials "E. F." but also wuth the suggestion of Heffalump, for he was physically a big man.
The protagonist (Gnossos Pappadopoulis) in Richard Fariña's 1966 novel Been Down So Long It Looks Like Up to Me believes his best friend to be named Heffalump for the majority of the novel, although Gnossos discovers in Cuba that Heffalump's birth name was Abraham Jackson White.