Duck Dodgers

Elmer: Should't I be hunting wabbits? This famous line is said by Elmer everytime he goes hunting for Bugs Bunny.

Singing in the Rain When the Cadet jumps down from Fudd's head after dancing on it, he says "Got'ta dance". This is a quote from the famous musical "Singing in the rain"

n/a: Lieutenant O'Hara In the Batman (1966) series, there was a character named Lieutenant O'Hara.

Whole episode: The whole episode
The concept of "The Fudd" is based on the Star Trek species The Borg. The one mind concept, the look, and the conversion are the same as the Borg

X-2, Cadet, and DD:

X-2: Are you sure this will work?

Cadet: I've seen it work before.

DD: Oh yeah? Where?

Cadet: Th-Th-Th-The Wizard of Oz.

X-2: Who's that?

DD: Um, he was one of our greatest military tacticians, you know. If ever there ever a wiz there was?

The Mother Fudd's ship contains millions of Fudd clones all marching, dressed up like and chanting like the guards at the Wicked Witch's castle. Cadet remembers the movie, The Wizard of Oz and suggests that they pull off the same stunt, disguising themselves as guards. Dodgers also tries to fool X-2 into thinking that the Wizard of Oz was one of Earth's greatest military tactitians, and later turns to tell us that there is no copyright infringements since they're doing a tribute.