Vexacus is a shark-themed bounty hunter and a rival and "sworn enemy" of Lothor. He wields a sword and a fan blade, and can summon a giant "land shark". On some occasions, he would use monsters that are Phantom Beast-themed.
Vexacus first comes to Earth hunting an alien - a Karminian - who can give her powers to someone when she dies. He fails in his attempt to capture these powers, and ends up stranded when his ship is shot down.
Vexacus becomes Lothor's head general, and often clashes with Zurgane.
This advances to a point where, after Zurgane's Hyper Zurganezord is destroyed, Vexacus wipes him out. He later does the same to Motodrone, but is stabbed in the back byMarah and Kapri, who arrange for his destruction at the hands of the Rangers. He returns again after the Abyss is opened, but is quickly defeated by Shane.