Here's more speculative evolution on more cryptids if they were real animals.
Beast of Bray Road, Michigan Dogman, and other bipedal wolf-like cryptids: Large, carnivorous marsupials whose ancestors, like the distantly related opossum, crossed into North America from South America. In a case of parallel evolution with Australia's meat-eating kangaroos, it evolved bipedalism, developing an extremely fast gallop so as to better compete with its placental rivals.
Devil Monkey: A species of monkey that evolved from a species of new world monkey from Latin America that found its way into North America. Due to convergent evolution, it evolved to resemble that of baboons notably a dog-like snout.
Ennedi Tiger: A surviving member of the machairodontinae family aka saber-toothed cats. The Ennedi Tiger evolved from one of the species that eventually moved up into the mountainous ranges and areas to avoid competition with lions, leopards, and scavengers given its fangs likely would have made it a slow eater.
Flatwoods Monster: A member of the giant salamander species alongside hellbenders, Chinese, and Japanese giant salamanders. On that night the proposed Flatwoods Monster was sighted, what those people saw was one of those salamanders which was leaning against a tree, and given how dark it was made it seem much bigger hence its eyes looking like they were at in front along with its arms. It somewhat takes up the niche of crocodilians given the colder environment that would be unsuitable for them.
Loch Ness Monster: A gargantuan species of newt that evolved a body structure similar to that of a plesiosaur and probably the largest amphibian alive reaching a length of 20-25 feet on average. Because of being an amphibian, it doesn't have to surface very often and like giant salamanders and hellbenders can stay hidden at the bottom of Loch Ness for long periods of time.
Nandi Bear: A gorilla-sized baboon in, which evolved to take over the niches left by the great apes when they became extinct in much of East Africa. Unlike their relatives, they live in small family groups instead of large troops, their size and food requirements keeping them from joining up in large bands. They are mostly vegetarian but will eat meat on a semi-regular basis.
Trunko: A species of whale that evolved a prehensile trunk using it to make rudimentary tools with which to dig up crustaceans and other prey.
Underwater Panther: On the ocean-like expanse of the Great Lakes of North America, a species of lynx has evolved a semi-aquatic lifestyle similar to the fishing cat of Asia. Chasing down fish, muskrat, beavers and frogs, the underwater panther also became adept at snagging fish right off the line or from the net as humans began to fish in the area. This mischievous habit combined with their haunting, eerie vocalizations has contributed to many Algonquian peoples such as the Ojibwe giving this animal a legendary status.
Water Lion: Like the Ennedi Tiger. Another surviving member of the machairodontinae family. This saber-toothed cat eventually evolved an aquatic lifestyle in order to avoid competition with other big cats like lions and leopards, and to allow them to eat meat which has been putrefied in water. Their fangs being used to dig up shellfish and turtles from riverbeds, or even to gain a purchase on slippery riverbanks.