As for the new snake, it's probably just a skin infection. But it could be a bad, bad, bad, very bad one. Nowadays there's a super fungus called Ophidiomyces ophiodiicola that causes something called snake fungal disease. It's very bad. It kills 80-90% of rattlesnakes who get it, and it's driven populations to extinction. Luckily it only kills about 40% of garter snakes in my experience. From this photo it's hard to say if it is or isn't that. Look it up and compare the pics you find with the snake. I was part of a team a few years back researching it, and I hope to god it isn't SFD. If it is, don't release the snake. If you have a garage or something far away from your snake room, buy a tub and keep it there. If it dies, bury or burn it. We don't want it spreading more than it has. If it is, bleach or alcohol your hands and don't touch your babies tonight. (Bleach or alcohol. Not both. Together they produce chloroform).Or feed them. Nothing. And if it isn't, I'd still keep it out of the snake room. And still wash up well. If it is SFD and that's all the worse it has it, it'll likely shed out of it in a few sheds. And handling your babies, I just sent that very answer to one of my customers.lol I'll copy and paste.