Panda-Z has five-minute episodes, with a hard-rock opening, and concerns the battles — mental and physical — of a group of robot animals. Silent-movie style, with text placards rather than voices.
Dogtato-kun (Jagainu-kun in Japanese) has 3.5-minute episodes, and it’s about cute little animal-vegetable hybrid creatures. A bit similar to Ocha-ken (Tea Dogs).
Pugyuru also clocks in at 3.5 minutes. It’s about a girl who gets a maid named Cheko-chan from the Country of Maids; Cheko is short, rubbery, runs on batteries, and her head is prone to popping off. She’s friends with an edible yuki-onna and has a squid for a rival. (The folks doing this one put the funny mushrooms on their pizza.)