Klarion kept Teekl with him at all times. This was something Doctor Fate noticed, and he attacked the cat rather than the witch boy. This made Klarion so mad that he was forced to retreat to save his anchor with the mortal plane.
When the Team confronted Klarion, Kid Flash remembered Teekl was Klarion's weakness. However, Klarion saw through this plan, and Teekl transformed into a much larger and feral cat creature. Superboy had his hands full, until Klarion retreated and summoned Teekl back with him.
Teekl was on its favorite spot, its master's shoulders, when Klarion controlled the Justice League. It carefully monitored the Leaguers, and told the witch boy that Red Arrow, Red Tornado and Black Canary had not responded to their renewed exposure to Starro-tech. Because Klarion kept to the background, Teekl survived the battle without a scratch, and was teleported away with its master and Vandal Savage when Klarion was at the point of losing control.
Klarion was overseeing the last phase of the Light's plan to release Tiamat and obtain the Tablet of Destiny. When he explained everything to the Team's Beta Squad, which had come to stop them, Teekl grabbed the Tablet and walked off, against the wishes of his master. The cat ran straight into Aqualad and his Alpha Squad. During the fight with Klarion and Blockbuster, the tablet was destroyed, prompting Klarion to escape with Teekl.
After the Light's summit with their erstwhile partners the Reach turned out to be a trap laid by Aqualad and the Team, Vandal Savage summoned Klarion from his ring. Teekl sat on its master's shoulder, and watched as the witch boy transmogrified a sword into a fire dragon. Klarion, while stroking Teekl's chin, activated a portal which whisked him, his cat, and Vandal away from the underground cave.
Teekl is Klarion's anchor on the earthly plain and if the cat were to be fatally injured or killed, its master would be thrown back to his own dimension. Klarion could boost Teekl's physical abilities, transforming into a large saber-tooth cat.
Teekl was designed by character designer Jerome Moore. Moore based Teekl's scraggly fur and whiskers on Mrs. Norris, the cat belonging to caretaker Argus Filch in the Harry Potter films. He also gave the cat's markings a rune-like quality, and included a vial/pendant on the collar that was based on the blood-filled necklaces worn by Angelina Jolie and Billy Bob Thornton when they were married.
This is Teekl's second animated appearance. The first was the The New Batman Adventures episode "The Demon Within".
Teekl's gender has varied in each version; Kirby's version is a female, and Morrison's version is male.