Everyone knows Rattlesnake and Coyote DNA just don't splice....
Trying to picture how they got together in the first place... I can't really picture a male coyote being able to, umm.... you know... with a rattlesnake. If actually attempted, you'd have a dead, split-open snake and a coyote with fang-marks on its willy.
A male snake and a female coyote, on the other hand... hmmm. Maybe it was just real cold out , and the snake found the coyote asleep in a cave, and wanted to find someplace cozy and warm to take a nap... snake is having real nice dream about female rattler, coyote wakes up, startles the j*** out of the snake, which then promptly exits, stage left.
There you have it. Darwin on steroids. Kinda disgusting, tho....