I can read your mind. You know the name of this place. You are now ready to enter the Cave of Bad Dreams. But, before you come in, I must tell you something... I have hidden a precious treasure inside. You can keep it for yourself, if you beat me to it. I’ll give you a head start, but don’t waste any time! If I catch you, I’ll show you no mercy...
~ Jano upon Rayman entering the Cave of Bad Dreams

Jano (commonly known as the Guardian of the Cave of Bad Dreams) is a character from Rayman 2: The Great Escape (and its remakes) in which he guards the Cave of Bad Dreams, a subterranean grotto in which the nightmares of Polokus are found and where his job is to ensure they are kept locked away. Jano also guards precious treasure, which until found by Rayman, was only rumoured to exist.

Actually, Jano isn't a villain. After the fight with Rayman, Jano offers his treasure to him as a reward. Rayman declines it and Jano then says him he made the right decision and gives him the Elixir of Life which Rayman needs for his friend Clark.

Jano also appears as a boss in the Rayman 3 game on GBA.