found an injured garter snake? help?

[StarFall]

i was walking home today and i found a garter snake in a puddle. it was not able to get out so i picked it up and it appears to be injured near its tail. it’s twisted up and a part is sticking out a bit. it looks like it’s scarred over maybe? but it’s twitching a lot. i can take pictures if needed. i’m not sure what to do. there’s a lot of outdoor cats in the neighborhood and i’d hate to see it get killed