Shadow Milk Cookie Plush?

Hii so my little sister (12) has been telling me about this game (I've never played) and she has been talking about this cookie that she likes. I want to buy her the plush but from my understanding he's no longer available? Does he come out again or would it realistically be easier to get it from a reseller? Sorry if these are silly questions, I just want to get her something nice 😭