The Pest

Not be be confused with the Vermin, a broader version of the Pest that also appears in familiar franchises.

That worthless dumbass who calls themselves the Hero's "teammate" that everyone would be better off without. The Pest more often gets themselves in trouble than not, earning them a low grade in value to the rest of the team. Pests are more commonly female than male since those characters tend to be less able to fend for themselves. Such vulnerable victims to danger can't be counted on to be aware of how terrible they are, making them even greater pains to the audience. If the creators know what they're doing and how to do it, they'll make the Pest an unbearable whiner or sassy ingrate who should be grateful they have friends who are willing to go through such treacheries to help them yet again. What hurts more about Pests is those around them are clueless to how much they should hate them. Anybody whose purpose we have to question might not do anything other than make things worse and should be sent off the team as soon as possible if not right this very moment.

Aside from being a terrible teammate to the Hero, a Pest is also any character the audience mostly dislikes, such as someone who clearly exists for merchandising or is too irritating or stupid for the audience to enjoy. They're characterized by their unbearable screaming, crying, and other high-pitched noises that turn the audience members' ears into faucets of blood. While screaming often goes unnoticed by those in the universe, crying and whining have a chance at being pointed out by people around the Pest.

UnRec
Don't do it. The Pest is more often than not a Useless Character your story can exist perfectly fine without. As such, it'd be better to see your franchise without one than a Pest at all. Like their familiar cousin, the Vermin, the Pest is prone to complaining and trouble-making, two aspects that do not fit an enjoyable character. Still, even with a low-tier role like this, a crafty writer can make treasure out of trash. The Pest's terrible behavior can be exaggerated to the point of hilarity where they throw an explosive fit over the tiniest issue. It can additionally be hinted that everyone else plots against this person. There's also the less relieving option to not do this and simply have the Pest be hated on by everyone for being alive. As long as they get punished for being eternally dissatisfied with the world around them, there's little harm in writing a good Pest into the story. Just don't have them interfere with the Main Team's missions.