I find this difficult for me, because there is a huge difference between me hating a character, and me making fun of a character.
I hate Slippy. Technically, I feel like the StarFox team is useful because they shoot things during hectic battles, which is a timesaver for me. Falco actually poses as a character that Fox can talk to and have a conversation that does not involve barrel rolls or U-Turns, given that Falco envies Fox. Peppy teaches you basic mechanics for flight, and it's useful, because after all those years, I had forgotten how to do certain tricks. Slippy... shows you the boss' health bar. Big whoop. Not only that, he also gets chased constantly, and at one point will get kidnapped. He also talks loudly, obnoxiously, constantly, and sounds like an 8-year old girl. Honestly, after so many times of hearing "Fox, get this guy off me!" I eventually tried to shoot Slippy down at the start of each mission when I could. Though, I will admit, he does deserve credit for building the Blue Sub, as well as the guns that Fox and Falco use in Super Smash Bros.