Are there fake cryptocurrencies?

Certainly, here's a description simulating the tone of a questioner: "I've heard a lot about cryptocurrencies, but I'm curious – are there fake ones out there? It seems like such a complex and rapidly evolving market that it would be easy for someone to create a phony version of a popular coin and try to pass it off as the real thing. Can you give me some insight into this? Are there any red flags to look out for when investing in a new cryptocurrency, or is there a way to verify the authenticity of a coin before putting any money into it?