Urban Legend?

This is most likely an urban legend, but it's not one I've heard before (if you have, please tell me) and it bears repeating here for mild entertainment value if nothing else.

So there's this friend of a friend of my girlfriend who owns a huge snake. (Please, leave your "huge snake" gags at the door - what are you, 13?) Like a python or something. And she's one of those weird chicks who gets off on walking about the house with the python draped all about her like Tom Baker's scarf, and then at night puts it back in its glass case thingy, though occasionally it does get out, but it wouldn't ever hurt her, so nothing to worry about, right?

Anyway, one day she notices the python is off its food. It won't touch the dead rats or bunny corpses or whatever it is you buy to fill up an 8 foot snake, and eventually she starts to worry about it, so she takes it to the vets.

"He's not eaten anything for like a whole week!"

"Well, I wouldn't worry about it too much. He seems pretty healthy to me."

"Phew. Because I was worried when the other night I woke up and he was lying out on the bed beside me - I thought he might be dead."

"Oh. Well. That puts a slightly different slant on things..."

The vet then goes on to explain that big snakes like this (it might not be a python, because obviously urban legend details get blurred in the retelling) will often starve themselves for weeks on end if they find a large enough prey that they intend to devour whole. And to make sure they can fit it all in, they will sometimes lay out alongside the body of the prey while they're fasting, just to make sure they can fit it all in one GULP.