Barbeln is a new character introduced in Metal Slug Attack.
Barbeln is an Invader that is a subspecies of Fedeln Metzelei, sharing many similar traits. Barbeln's wings are more specialized in offense, using her wings to cut down enemy troops and unleash blasts of galactic energy to destroy everything caught in the blast radius.
Due to this, she enjoys the thrill of a fight. She cares for Fedeln, protecting him whenever possible, and is worried that he isn't aggressive enough despite his devastating power.
First appearing in "Beautiful Fighter", Barbeln arrives before the Ptolemaic Army can kill Fedeln with their Sapphire Turtle. She learned that he became a Metzelei, though is still disappointed that he hadn't changed from their last meeting. Fedeln warns her that he is still poisonous, but she states that years of training has made her resistant to his poison. She takes on the Sapphire Turtle while ordering him to retreat.
Her speed prevents the Sapphire Turtle and Claw Unit from catching her, but she soon senses Fedeln in danger and retreats. She spots Fedeln casually talking with Sally and stops the two. Fedeln states that he wants to make her his friend. Though Barbeln states that the human looks appetizing, she states that he needs Invader companions and not weird lifeforms as she takes him away.
- Metal Slug: Commander (2020)