Katalina is a new character introduced in Metal Slug Attack.
Katalina serves as a scientist in the Rebel Army and is a member of ACE. She developed the Marinesk, a slug-like tank that utilizes energy particles and compressed air, combining both in order to generate energy-based attacks which can be turned into an orb or tornado, the latter of which is assisted with what appears to be a book she carries with her.
First appearing in "Task Force 10th", Katalina learns from a soldier that the front lines are struggling to defeat the enemy. She decides to personally intervene, ordering the soldier to finish up her Marinesk. Upon arrival, she single-handedly routs the clone invaders and rallies the soldiers to destroy the Clone Incubator generating them.
Sometime later, Katalina leads an operation against the Regular Army with a Golden Cabrakan and numerous self-destructing pods. She is met by Avvio, who tries to hit on her, but she ignores his attempts to flirt with her. Eri appears soon after and tries to apprehend her, but she directs another group of pods to cover her escape.