yes, even old school/world pets should get some love and attention now and then. the crimson snake's animation is basic (casually looks around, sticks out its tongue from time to time, and slithers to follow after you) and it's graphics can't compare with some of the newer in game vanity pets, but i adore my snake friend mainly for sentimental reasons.
why i love it
this companion was given to me by a guildie as an in-game wedding gift (how RP of me, i know heh), and it was my first snake pet. it was also my first horde pet, being that it was gifted to me before burning crusade; before anyone could buy it from the neutral vendor in netherstorm.
what i would change
i would definitely update the graphics of this companion and give the eyes more detail. at the moment, they blend in with the rest of the body so well, it's almost as if it has no eyes at all. i'm walking around with a blind snake and it's heartbreaking!
i would also give it an on-click sound effect, much like a couple of the newer vanity pets have. perhaps a small hissing sound whenever you target it.
as for an animation (because i love my animated and interactable pets), i'm not sure any type of special animation would suit this one. at first i thought about maybe having it shed its skin from time to time, but i'm not entirely sure that's something the majority of players want to see (it IS kind of gross if you dwell on it too deeply).
one animation that would probably be PC enough is an idle animation. whenever idle, the snake could curl up into a tight coil and fall asleep. of course it's rare for blizzard to go back and change/update animations for most pets, so i won't hold my breath.
all in all, it's great for lower level characters who may not have access to higher level companions yet, and even though it's quite old and may need some updating, the crimson snake is still a pet that i would not go without. whenever i bring it out via my random pet macro, it makes me all nostalgic. :)