@graf @j You're really aging me here.

Idk what snakes are in your area, but generally venom is fairly fast acting because snakes ain't tracking down their prey too far. So you'd start seeing other signs if the bite was venomous.

It might need to see a vet, but I don't believe it will need an emergency vet. ER vets are more for severe traumatic injuries and cases where the animal may die if not treated. I'd make an appointment but skip the ER unless something drastic happens.

If the cat is putting weight on it it isn't likely a break, but I've seen cats do some crazy shit before. Definitely keep the cat indoors until this resolves.