in one quite old snakebytesTV episode a ball python x green tree python hybrid has been shown.

definitively weird, because they behave and move so differently. different size of teeth, different number of heat pits, one doesnt hide but is carmouflaged and hangs around in trees and only hatchlings live on the ground, the other hides and always lives on the ground.

its both pythons and the number of chromosomes is the same (so, theoretically, F2 hybrids or crossing back could be possible). but apart from that, the species are wildly different, even in captivity they need different enclosures.