The definitive history of the Marx Bros. in animation has yet to be writ,
and I may be the man to write it.
Their debut as cartoon characters came not long after they made their
screen debuts, and they have been favorites of animators ever since,
from "Looney Toones" to "Animaniacs" and beyond. (Coming soon to
Grouchobeer Productions?)
Their appearances are usually brief gag cameos, often in cartoons
that feature caricatures of many other Hollywood stars. Sometimes
characters like Bugs Bunny or Popeye would impersonate them. A
planned series in the 1960's (there were other cartoon series
of Laurel & Hardy, Abbott & Costello, and The Three Stooges) was
never made and a more recent (1990's) pilot for an Adult Swim-type
cartoon has never been shown on television-- a tragedy, because
it is a brilliant conceit carried off magnificently. The writing, acting,
animation, and direction are all top-notch. What doomed this
production-- and perhaps any further Marx toons-- is the fact that the
rights to Groucho Marx belong to Groucho Marx Productions, Inc.,
while Chico and Harpo's rights are licensed by another company
(which is now owned by Microsoft.)
I hasten to add that with the exception of an animated version of the
Napoleon scene from
I'll Say She Is made for TV in the seventies
where Groucho revisited the character he created on Broadway in
1925, they never supplied the voices for any of these cartoons, and
the voices range from OK to awful, as do the likenesses.
The real Marx Bros. were under contract first to Paramount and later
to MGM, but do not appear in many cartoons for those studios that I
am aware of, although Popeye's first solo cartoon did not feature his
now-familiar theme, but rather an instrumental version of "Whatever
t Is, I'm Against It" from
Horsefeathers. Groucho also makes a gag
cameo in Popeye's version of William Tell, which was animated
by the great Shamus Culhane, who later married Chico's
daughter Maxine. (Culhane also included caricatures of his future
uncles-in-law Groucho and Harpo-- but no Chico-- in his cartoon
The Brave Tin Soldier.) This is rather typical, as Groucho and
Harpo tend to appear the most often, with Chico lagging behind.
But he is represented, and so even is Zeppo, albeit in
mostly-forgotten series like "Buddy", "Bosko", and "Flip the Frog".
The animated Marxes probably "appeared" most often for rival
studios Warners and Disney. Following are screen grabs from
Warners'
Hollywood Steps Out.
.

Harpo gives Garbo a hotfoot on her really big shoe...

... and prepares to burst stripper Sally Strand's bubble.

Hey, that's not Thelma Todd!

(From http://tesla.liketelevision.com )