"It's a Jungle Out There" was the original title of the episode "A Ghost Grows in Brooklyn" until it was changed to reflect a literary reference.
The entity known as Ral received an entry in the 2016 tie-in book "Tobin's Spirit Guide - Official Ghostbusters Edition" on page 44 and 45, where it is identified as a Class VII, Semicorporeal, anchored to a statue. Influences animals by way of partial possession.
The voice actors were recorded on May 18 and June 10, 1987.
Peter Venkman mentions Marlin Perkins, a famous zoologist and former host of "Wild Kingdom," while trying to bust Rall.