Characters are the core foundation of any popular sitcom, and when it comes to recommendable ones, there aren't many better than Friends and How I Met Your Mother. The characters involved in both are beloved by millions for all sorts of individual quirks, personalities and contributions to their respective casts. Both groups of characters harness the ability to rotate through being a protagonist or sharing the limelight, all preventing each other from just decorating the background.
But when all that doesn't seem like enough, why not bring in a celebrity for a cameo? Fans love to talk about the one time that guy was in Friends, or what when that famous actress did a cameo in How I Met Your Mother. Though many celebrities are so well-known they'll stick out immediately, it's always fun to spot one out of nowhere.
Throughout the years, both TV shows have enlisted Hollywood's elite to make one-off appearances in various episodes - but can you identify which red carpet regular appeared on which show?