5. Cat Bowser - Super Mario 3D World
When one thinks of truly iconic video game villains, Bowser is going to be near the top, if not at the pinnacle of that list, and it's with good reason. This spikey brute has been the bane of Mario's entire career, constantly abducting Princess Peach or ruining everyone's fun with his desire to rule the galaxy.
Plus his design is just outstandingly cool.
That being said, he's had a few duff appearances across the years. For example, the fear of seeing his junk being exposed by tipping his bathwater in Super Mario Sunshine was deadlier than anything he could actually do to the player, but this was nothing compared to Cat Bowser from Super Mario 3D World.
Because. I mean, how can you take a monstrous evil seriously when their ultimate form is something that looks this adorable. Look at the pose he makes! It was as if Nintendo wrote him off as ever being threatening again.
Now the subsequent boss battle itself is pretty challenging but it's always punctuated by the fact that Bowser, the greatest evil of the land, looks like Hello Kitty did him a makeover.