These are spider themed ponies I made as characters on Ashes.Town (and Pony.Town).
On Ashes Town (which is based in the Fallout Equestria world) they are the result of radiation causing mutations/crossing of ponies and spiders. Some like these are more pony than spider (and are sociable), and there's some that are vice versa (and only view something as a threat or prey). As a pony they still have spider abilities. Ones like Gardenia and Black Widow can shoot a magic beam that wraps their prey in spider silk, at which point they bite and inject their venom . Ones like Bluesy can only pounce on and bite/ inject venom. Ones that are more pony than spider have learned how to spit their venom into the eyes of anything attacking them.
In addition to these 3 types, I also made some based on the Fly-der (those flying spiders that inhabit Equestria) , Brown Recluse, and Brazilian Wandering, though I haven't made "more pony than spider" versions of them.
As for diet: Gardens only go after bugs, while others will go after those, and larger beings, including ponies. Widow and Bluesy have killed and made into dinner a few unfortunate slavers who though they were normal ponies, and tried to catch them.

Outside of AT: They're just ponies with spider coloring/markings (Black Widow themed ones have been a favorite of mine).