Archive Panic: The series lasted 192 short subjects, most of which aren't available on DVD.
Big-Lipped Alligator Moment: Late in "Hells Heels", there's an unusual non-sequitur gag (doubling as a Visual Pun) where the sheriff's kid drinks an entire pond dry, revealing an orchestra pit consisting of a walrus and misc. animals, who proceed to play an off key rendition of "How Dry I Am".
"One More Time", a licensed song used in "Radio Rhythm" (and coincidentally was also used in a Merrie Melodies short, called "One More Time" in 1931).
"New Deals Coming As Soon As You're Born", the ending song of "Confidence".
"The Egg Cracker Suite" (Oswald's final Lantz cartoon) has a jaunty jazz leitmotif play throughout, along with, like any good cartoon series can't do without, a rendition of Hungarian Rhapsody (provided by clucking chickens no less).
Dork Age: Any of his non-Disney Shorts. The early Lantz shorts and the batch that Bill Nolan directed by himself do have their fans (largely due to their Mind Screw qualities), but few consider them to be up there with the original Disney shorts.
Ear Worm: The "My, My, Yes, Yes!" number from "Radio Rhythm".
Genius Bonus: In the Lantz Oswald short "Sky Larks", Oswald and his friend visit the planet Mars, where every living thing on the planet is a weapon. This seems like surreal silliness for its own sake, until you realize it's a nod to the Roman God Mars, who is associated with war.
Hilarious in Hindsight: In the early Lantz Oswalds, Oswald, a character created by Disney, was voiced by Pinto Colvig, who would later go on to voice another Disney character; Goofy!
One of the gags in the Disney shorts has Oswald using a goat to make music, a gag that would end up being recycled in the breakout hit of his successor.
The Christmas-themed short "Empty Socks," believed lost for decades, was discovered shortly before Christmas of 2014. Then in late 2015, another once-lost Christmas themed Oswald short, "Sleigh Bells", was found!
The opening and the phantom from "Spooks" are rather creepy too, especially the scene where the Phantom is unmasked.
The montage midway through "Confidence" when Oswald is trying to find help for his ailing farm, amid the American economy going into shambles, while screaming "DOCTOR!"
Retroactive Recognition: While Oswald's final theatrical short, "The Egg Cracker Suite" got little attention at the time of its original release, it's since become noteworthy because of who Walter Lantz hired to voice Oswald, namely a little-known (at the time) radio actress by the name of June Foray, who would go on to become arguably the most famous animation voice actress of all-time.
Seasonal Rot: While not as liked as the silent Disney shorts, the Lantz Oswalds from the early 30's are still perfectly enjoyable, creatively animated cartoons. Unfortunately, by the mid to late 30's, the shorts took a substantial downslide in entertainment when it abandoned its humorous and surreal roots in favor of more cutesy, Disney like material.
This also applies to the post-Disney Charles Mintz shorts, which are universally considered inferior to Disney's Oswald shorts.
Tastes Like Diabetes: A common criticism of the "White Oswald" shorts that Lantz started to produce from 1935 onward. Most of the Lantz entries after the first year or so tended to be very cutesy, but it became overwhelming after the redesign.
Tearjerker: After Walt Disney and Ub Iwerks stopped working on the character, he would continue to decline in popularity until he was almost completely forgotten. Look at what happens to him in Epic Mickey after that.
The Woobie: Part of his appeal and new found popularity. Especially taken into account that the poor character was taken away from Walt and unable to have the glory and fame Mickey Mouse and by extension, Disney made for itself. Even after Epic Mickey and its sequel gave him a revamp and a great return, he has yet to fully appear anywhere else. He at least have some love at the Disney parks.