Okay, between all the versions of Crowley… the Book doesn't really give us any detail for why Crowley is a snake. I mean, as far as we know he could’ve been Serpent-Adjacent even before he Sauntered Vaguely Downwards (but probably not). Still, most of the ways his Snake-ness manifest is in physical traits that he doesn’t necessarily have control over (his eyes that he keeps constantly hidden even when he doesn't have to, lack of blinking, his hissing is specifically mentioned to be involuntary, his ‘snakeskin shoes’ are most likely just his fucked-up feet), and he did change his name from something explicitly Snake-themed because he felt it just didn’t suit him enough. So I mean, it doesn’t seem like he dislikes being a snake, but it’s more of just a... Neutral Fact of his Physical Existence at best.
Show Crowley is in a very similar situation, but with the way that Hell is designed in that Show, does certainly imply that Demons probably all just got inflicted with an Animal soon after they Fall, Crowley almost definitely got no choice in the matter and we also have even more explicit discussion on the fact he changed his name to distance himself from the snake-like connotations of ‘Crawly’.
But still, at the same time, he does lean into being a snake. Show Crowley especially has some very Difficult feelings about being a Demon sometimes, but it seems like the Snake aspect of it is something he’s more comfortable with. He does incorporate Snake-themed stuff into his aesthetic deliberately. I mean, maybe the clothes (like the Snake-themed belt and the Snakeskin Shoes he has in his modern-day outfits), are kinda Hell-mandated, or manifest Snake-theming as a side-effect of being created from Demonic Miracles, but I dunno if Hell would insist that Crowley has to get a Snake Doorbell for the flat? I think Crowley must’ve chosen it?
Then the two Crowleys who are confirmed to have chosen to be a serpent are Radio Crowley and Musical Crowley. Radio Crowley also seems to be actually just wearing snakeskin shoes, and Hastur and Ligur seem consider it one of the things that make him a Flash Bastard, so it's not like a Demon Thing. And his only comment about his old name is just that 'he doesn't like that name', so as far as we know that wasn't about the snake-iness of the name, maybe he just thought it was a silly snakey name. He'll be fine with a snake-themed name it was just more dignified about it.
But, well, he does otherwise seem to have a similar Neutral relationship with his snakeiness as Book!Crowley and… maybe this is just how I interpret the line, and I know that a lot of Radio Omens dialogue can have a kinda Weird Quality to it due to the respectable-but-complicated aspiration of conveying the entire Good Omens narrative via dialogue and retain as much of the original text as possible, but…
The way the conversation flows from 'you chose to be a serpent' and 'they just said, Get up there and make some trouble!' seems to imply to me that, like… the way I'm imagining it is Hell being like 'okay, we need someone to go up to Eden, we talked to Marketing and it was settled that it should be in the form of a Serpent', and Crowley being like 'um, yeah, sure, I'll do it'. So he chose to be a Serpent, but maybe more in the way that the employee volunteering to wear the Chuck-E-Cheese suit that day is choosing to be the rat... If that person then had rat-themed features incorporated into their physical body for all eternity....
But Musical Crowley very explicitly brags that he came up with the idea of being a Snake all on his own, he got told to 'get up there and make some troubles', he saw the Tree and immediately decided that he should transform into a Snake. It's made very clear that if he just had another animal pop into his head, the Musical Omens Bible would've told the story of how Humanity was doomed to Original Sin by a Cat or a Walrus or a Guinea Pig. Musical Crowley thinks that choosing a snake was super-cool and very iconic of him and he also deliberately choose to lean into the aesthetic in the modern-day. Snakeskin Shoes are actually one of the top things he lists in his song about what he'd miss about Earth because there's none of that in Hell.
And I think that means Musical Crowley is the one version of Crowley Goodomens that you can clearly unambiguously label as a Scalie.
