The Pest

Not to 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 from the rest of the team. Pests are slightly more commonly female than male since those characters are portrayed as 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 madness 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.

The Pest is, beyond a shadow of a doubt, Utter Trash. They're deficient in virtually every aspect that can help them amount to a worthy ally to the Hero. They took no time to learn any abilities that could assist in or outside of combat, so they waste most of their time standing idly by while the others do all the actual work. Their inability to act independently can result in cowardice that sends them running the other way once the smallest enemy appears. The universe may align itself in such a sadistic way that the Pest somehow manages to become the only hope for their team to succeed in a task crucial to their adventure. All it takes to make them fail is one stray baddie who breaks their resolve and scare them to abandon the more important people. For the sake of the audience's nerves, this incompetence hopefully annoys the Leader so much that they address the Pest's worthlessness and threatens to kick them off the team. What can make the Pest even more insufferable is if they put up an argument against the legitimate disapproval for them. They may rely on Lolgic to back up their awful performance and defend their inability to show some agency or courage. The audience's hatred for the Pest reaches its peak once all of this fails to pay off climatically. If the Pest's crap-assed idiocy becomes the engine of some drama, the audience could give a partial excuse. However, their spot on the team being wasted not contributing to the story gets fingers pointed at them for standing as an unsavory malaise in the franchise.

Aside from being an absolutely terrible teammate to the Hero, a Pest has the bad habit of being the one audience dislikes the most. 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. Meta-wise, the Pest may only exist for merchandising or be too irritating or stupid for the audience to enjoy. Time blown on them would be best reallocated to anyone else or developing the plot. The pains of What Could Have Been will burden the audience with discontent with the franchise for making such poor decisions.

UnRec
Don't do it. The Pest is in all likelihood a Useless Character your story can exist perfectly fine without. As such, it'd be better to see your franchise without one. 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 option to merely have the Pest be hated on by everyone for being alive. It'd be a relief for the audience to see others get fed up with the Pest and reflect their own desires. As long as they get punished for being garbage, there's little harm in writing a good Pest into the story. Just don't have them interfere with the Main Team's missions.