At that time, Clampett was already animating for Tex Avery and he desperately wanted the chance to direct. Wanting to direct; Leon Schlesinger was initially contracted by RKO Radio Pictures to create an animated Technicolor sequence in 'When's Your Birthday' and Leon gave Clampett a trial to direct that sequence in order to qualify him as a cartoon director to work on the Porky cartoons. The plot of this animated sequence talks about the origins of the zodiac chart. This was really Bob Clampett's first directorial work. This sequence was filmed in Technicolor, however despite being so rare over the years and being hard to find; most of the prints of this sequence is in fact filmed in black-and-white and it's not known if the Technicolor prints still exist today.
What confuses me is that this film was released to theaters in February 19, 1937 but in 'Hollywood Cartoons' Clampett was promoted to a director, according to the book and that's when he made cartoons at the Iwerks studio. Although I imagine this would've occurred at around Fall 1936 when he was given a trial to direct the animated sequence of the film before released to theatres; and as the film was released to theatres - Clampett and Jones would've been at the Iwerks studio where Clampett would've heard his trial was successful and given the director's chair on the spot. I don't know if this is true but that's my theory. It's a shame that Clampett didn't get any screen credit for his work in the film but screen credits were scarce back then; and animation artists wouldn't be credited on distributing pictures with animated dream sequences.
The animated sequence occurs at the beginning of the film after the screen credits. The title card begins to read; and this was definitely Clampett's idea to use: The events and characters depicted in this photoplay are fictitious. Any similarity to actual persons, either living or dead, is purely co-incidental. Those descriptions of course were in feature films back then.
The narrator then starts to read out the zodiac chart as the zodiacs show their resemblances such as "Cancer" resembles a crab, "Leo" a lion, etc. A professor then begins the sequence as an animated hand drawn realistically points with a stick explaining the Astrological chart. The professor appears to be speaking in an Irish accent but I think this is voiced by Joe E. Brown and cracking up some dated jokes, by mentioning the Chicago World's Fair once. The camera then views some of the animals like Aries which is a ram, Sagittarius resembles a centaur, Taurus is a bull, and that's all that is pointed out. The hand holding the stick then spins the chart; as we go straight into the universe.
Inside the heaven we find the zodiac figures inside as this paradise for them. There is a bull puffing on a cigar sitting on top of the clouds; with a half naked girl sitting next to the bull which is meant to represent Virgo. The moon and bull wink at each other as the narrator explains the story. The bull then walks down to find a crab (represents 'Cancer') is rather frightened of the bull and dives under the cloud. The bull then charges forward as the 'Taurus' is supposed to be superior with all the other zodiacs prancing on the floor obeying the Taurus. The Taurus then walks up to the Sagittarius that is also obeying. The Taurus then turns to find that there is a lack of moonshine as the moon has a happy face once the clouds fade in.
The rest of the animated sequence then focuses on the bull in which the Sagittarius beats it up and it ends with the bull knocked down with the moonshine watching what is being seen; and it concludes with the bull knocked out. After being knocked out you find that the knocked-out Taurus' pose fades to live action of a knocked-out boxer; and that's the end of the animated segment. You can find that much of this sequence shows Chuck Jones' character layouts and animation, but I believe that Bob Clampett did parts of the animation too. Bob Clampett mentioned that the model of Sagittarius is in fact Bobe Cannon who was animating for Tex Avery and also went to join Bob Clampett as Bob Clampett mentioned so in a Michael Barrier interview describing that Cannon had a "heroic figure".
The animated sequence isn't particularly special and it's very unmemorable but it was very important for Bob Clampett and it was enough to impress Leon to be given the directorial chair; so without this animated segment - it wouldn't have been possible for Clampett to begin directing. It's a shame that there aren't any known color prints available to the public unless private collectors might own some. The story, well I couldn't quite understand the narration in the copy I was watching but it appeared to be poking fun of the Sagittarius and the Taurus; but believe me I know very little of zodiac charts (except I'm a Leo) and I don't believe in astrology so I don't know much of the meaning of this animated sequence; except the plot focuses on Joe E. Brown's character who believes in astrology which is why it fits into the sequence. At least the good part of this animated segment is that Clampett would go on to direct some very funny cartoons for Warner Bros. which include some of my favourite Daffy Duck cartoons.
Here you can watch the whole sequence that is available on YouTube thanks to Cartoon Brew who written a post about it a couple of years ago. It's also available on DVD in the US.