Ball Weevil can be hurt by his own plasma balls if they are reflected at him. He can also get stuck in his own plasma.
Ball Weevil is vulnerable to being trapped by a member of Terroranchula's species, his natural predator.
Ball Weevil's plasma can be neutralized by a Terroranchula's webs. It is also useless against a species capable of withstanding it, such as Arburian Pelarotas.
Ball Weevil's small size puts him at a disadvantage against larger opponents such as Terroranchula.
Ball Weevil cannot breathe underwater. He also cannot use his plasma balls as a helmet because he can't breathe in slime.
While he can absorb matter and energy using his plasma, Ball Weevil cannot absorb gases.