I only had 1 teacher that had a class pet and it was probably like my first grade or kindergarten teacher, it was just a couple fish. One day during class they all died and we watched the teacher throw the bodies away in the trash lmao.
in kindergarten my class got a pet fish, the teachers wanted everyone to make up/choose a name for it. i specifically remember wanting to name the fish “grape” and everyone looked at me funny lmao
also another time we raised caterpillars to learn about their lifecycle. after they turned into butterflies we released them at our school’s backyard.
I remember this one elementary school class I was in had a small fish tank with a betta in it. I don't remember its name, but what I do remember was that it was probably named after a Spongebob character.
I never had any classes with pets until my sophomore year. My history teacher at the time kept a snake, and she let me hold it when I needed a little sensory stimulation. The snake doesn't mind, and it hasn't bitten me before.
More recently, in my science class, there was a bigger fish tank in the back and it held three fish.
I would also like to mention that I know of this one teacher who brought his pet rabbit to school. I saw him walking and holding the rabbit's cage when I was waiting to be picked up by my parents.
I don't think there were any class pets throughout all my years of schooling. I don't recall any, at least. Kind of a shame, as it's kind of a cute idea.