Mad Monster Party? (1967)
The Character "It" is an unnamed King Kong. The film with the planes attacking him references the 1933 film
"Now, friends, you'll discover who was the original Batman."
Referenced by one of the characters
The Filmbuff mentions Boris Karloff's role
South Jersey Sam lists this as a Rankin/Bass movie
Hewy describes these all in one film.
Spoofs the scene where the planes are attacking King Kong.