I've been playing with Alibaba's Qwen 2.5 model and I've had it claim to be Claude. (Though it usually claims to be Llama, and it seems to think it's a literal llama, i.e. it identifies as an animal, "among other things".)

Claude also sometimes claims/claimed that it is ChatGPT or a model by OpenAI. Same with LLaMa. It's just polluated training data.