The Prison Panic is an excellent Oswald cartoon with some very fine animation, I was particularly impressed by the animation provided by Pinto Colvig, I thought he was mainly in charge of voices and music but I see that he was also a very good animator.
Pinto Colvig was an animator, screenwriter, dubbing artist and musician all rolled into one ! It's also worth noting that Colvig was a pioneer of sound animation, since his first cartoon, "Blue Note" (1928), was released around the same time as Disney's famous "Steamboat Willie", but unfortunately for him, Pinto couldn't find a producer willing to distribute his cartoon. Needless to say, Colvig was a key player in the Lantz studio, helping the Oswald cartoons become true musicals; the company never recovered from his departure for Disney, despite Lantz's efforts to hire experienced animators like Frank Sherman and Vet Anderson, both of whom were old acquaintances of Bill Nolan (Sherman in particular had studied at the same high school as Nolan and they were very good friends).
It seems to me that Vet Anderson's animation is much lumpier and has more exaggerated facial expressions, but I could be wrong as I'm mostly only familiar with his late work for Lantz and Eshbaugh. Can you show me some of Vet's animation on Aesop's Fables so I can get an idea of his animation in the silent era ?
Although not a silent film, I think the Aesop's Fables cartoon most representative of Vet Anderson's work is "Laundry Blues" (1930). Here you can see the full influence of his previous profession as a caricaturist, as his facial designs for the characters were taken to extremes for comic purposes, and it works very well: his drawings of the Chinese with the protruding cheekbones and big teeth protruding from the mouth contrast clearly with the rounder, smoother style of Mannie Davis and Harry Bailey. Anderson shared scenes with these two animators, respectively in the scene where the waiter falls into the basin for Davis and the scene where four singers perform a beautiful version of "Chinatown, my Chinatown" for Bailey; I also think that Vet animated all the scenes featuring this Chinese butler, so I'm pretty sure that he designed this character, especially as he seems to be a caricature of Rudy Vallée (the real Vallée appears in a photo in this cartoon).