This Pokémon is characterized by moving by crawling on its own body (i.e., slithering, from which it gets its current name). Although it has wing-like structures on its back, it apparently cannot use them to fly, as they are not developed. Furthermore, although it usually moves by crawling, when attacking it can adopt a bipedal stance, standing on its legs.

Despite crawling on its belly most of the time, it is very physically powerful and musculed, and can stand up on its strong back feet. Although its massive wings are rudimentary, it can expand and flap them to deter or threaten its enemies.

Slither Wing is a supposed ancient Pokémon related to Volcarona. However, Slither Wing can be a counterpart of Volcarona from another timeline. Its true origin is unknown.

After beating The Gym Leader Kofu in Cascarrafa, you went to the West Province (Area Two), finding a those pokémon that you usually would find (Naclstack, Girafarigs, Garchomps, Tropious, etc).

All looked normal until you noticed some unusual and imponent pokémon slithering across the field, and it was nothing more than... Slither Wings.

Didn't Slither wing species was only found in Area Zero? Yep. For starters, the Slither Wing species doesn't have to be doing anything here. But there is a whole pack wandering around like if they was just some pokémon more, instead just being Paradox Pokémon in an unfamiliar territory.