Dr Anton Sevarius is a mad scientist who's skills with gene mapping and splicing have gone under scrutiny from the scientific community. Xanatos felt he was useful and has hired him on many different circumstances.
He was first hired to create a clone of Goliath. The Clone hired Anton to kidnap him and ransom him for money.
While The clone was growin Xanatose had him create gargoyle like creatures using wild cat, eel, bat and human dna. but the main objective was to mutuate humans into winged catlike creatures.
Goliath kidnapped Sevarius and forced him to create an antidote to his mutation. Instead the doctor fooled Goliath and made a poison instead. The poison was never used.
Sevarius went out on his own and tried to track down the Loch Ness Monster before being hired by Thailog to create a clan, and Dominique Destine to develope a carrier gene.