TIL these were real creatures that existed

From Wikipedia: Cotylorhynchus is an extinct genus of herbivorous caseid synapsids that lived during the late Lower Permian (Kungurian) and possibly the early Middle Permian (Roadian) in what is now Texas and Oklahoma in the United States.

Pic related

Some members of this genus could grow to ~6 m long and weigh 500 kg. Yet its skull was no larger than ours and quite a bit less, shall we say, capacious in the braincase department.

Whatever its dentition up there might suggest, it was an herbivore as you probably guessed from the rest of its features. Embarrassingly, as a synapsid, we're more closely related to this thing than dinosaurs. I get everyone's got a dark horse (or in this case a dumb horse) somewhere on the family tree. And humanity as a whole has an awful lot of these.

From Wikipedia: Estemmenosuchus (meaning "crowned crocodile" in Greek) is an extinct genus of large, early omnivorous therapsid. It is believed and interpreted to have lived during the middle part of the Middle Permian around 267 million years ago. The two species, E. uralensis and E. mirabilis, are characterised by distinctive horn-like structures, which were probably used for intra-specific display.

These hippo-gators with Corsola hats are also distant relatives of ours, being in the synapsid clade. The two species in the genus could reach 2 and 3m long respectively. Their genus is among the first to have developed differentiated teeth for different purposes.

And then there's Eryops, the polar opposite of Cotylorhynchus with a head somewhere between 1/4 and 1/3 of its total body length.
From Wikipedia: Eryops (from Greek eryein, 'drawn-out' + ops, 'face', because most of its skull was in front of its eyes) is a genus of extinct, amphibious temnospondyls. It contains the single species Eryops megacephalus, the fossils of which are found mainly in early Permian (about 295 million years ago) rocks of the Texas Red Beds, located in Archer County, Texas. Fossils have also been found in late Carboniferous period rocks from New Mexico. Several complete skeletons of Eryops have been found in lower Permian rocks, but skull bones and teeth are its most common fossils.

Fortunately, as this creature that looks like a croc hooked up with a bullfrog is on another branch of the evolutionary tree, the one that became amphibians. And the weird thing is, the temnospondyl order is full of genera that look like crocodiles shot out of cannons into concrete walls, mostly in the family Dissorophidae, which Eryops is ironically not part of. Eryops is part of family Eryopidae, most of whose members are less horizontally challenged. Meanwhile over in Dissorophidae, there's...

Genus Kamacops, containing only K. acervalis, a foot-long specimen from Russia.

From Wikipedia: Cacops ("ugly look" for its strange appearance), is a genus of dissorophid temnospondyls from the Kungurian stage of the early Permian of the United States. Cacops is one of the few olsoniforms (dissorophids and the larger trematopids) whose ontogeny (development from egg to adult) is known. Cacops fossils were almost exclusively known from the Cacops Bone Bed of the Lower Permian Arroyo Formation of Texas for much of the 20th century. New material collected from the Dolese Brothers Quarry, near Richards Spur, Oklahoma in the past few decades has been recovered, painting a clearer picture of what the animal looked and acted like.

There were 3 species in this neckless genus, and they were probably predatory despite being only about 0.4 m long, among the largest in their family. The above reconstruction is half of what convinced me to make this post (the other being #1).

And here's Zygosaurus Iucius, another cringing baby croc in a mono-species genus that is actually amphibious. It was about 20 cm and lived in the mid-to-late Permian in what is now Russia. Back then Eurasia was rotated about 90 degrees counterclockwise and so the part that is modern-day Russia extended from roughly its current latitude to about as far south as Florida.