Perhaps someone asked already, but how are Collin's parents half snakes, and Collin is a full snake?
they’re all nagas! which in the PDverse, range full spectrum from ‘big talking snake’ to ‘snake-like people.’
nagas are all born as snakes, but as they get older, most can start taking more humanoid traits with practice, and shift back and forth, although many have a ‘cap’ on how good they can get at it. the most common cap is the conventional naga - mostly human from the waist up, snake from the waist down (though its also common for their humanoid upper half to still have a face that’s more snake than human, or for an individual naga to be most comfortable in a form with less humanoid traits than they can emulate).
being able to form functional legs is relatively rare, and shifting away their tails altogether even moreso.
collin’s parents have the standard limit, while collin himself can’t morph more humanoid traits at all - although it’s not necessarily because it was his natural cap. he Did A Hubris and got mode-locked as a child before he ever got any good at shifting. he doesn’t mind it any at this point.
anywho here’s his parents shifted into Big Snake mode