Eight Triceratons Transmatted to Earth when Leatherhead and his Utrom friend Dr. X tested their second attempt to build a working Transmat Device to get him "home" to the Utrom homeworld on Leonardo. The Triceratons had been looking for the Turtles for some time, and seized the opportunity to send a commando unit led by Captain Zak. Leonardo nearly killed one of the eight Triceratons with their own firearms, though Leonardo, Michaelangelo , Leatherhead, and Dr. X had to escape from harm's way. Lured by the homing beacon sent from the Turtles' aircar, Captain Zak has one of his Triceraton commandos translocate to the signal, appearing directly on top of the aircar as Donatello unsuspectingly pilots it home with Horridus/Sara. The Turtles managed to fight the Triceraton invasion to its climax, with the invaluable help and savage force of Leatherhead, who, along with the last Triceraton standing, was transmatted away to parts unknown (TMNT Vol. 3, #19 - 21).