Tokka is an ancient Volcanthian Fire Beast, one of the six Cosmic Monsters, and the guardian of the third piece of the Heart of Darkness on the planet Magdomar. It is described as a fire-breathing kaiju. Tokka was also the parent of Chompy Picasso.
Tokka was entrusted by the Utrom to guard the third fragment of the Heart of Darkness with its life. When the Triceratons and Turtles come for the fragment, Tokka emerges from the lava and engages the Triceratons. When she hears the cries of her offspring, Chompy Picasso, and turns to find Chompy in the hands of April and Casey, April freely passes Chompy to Tokka, saying she's not charging for babysitting. Just as the Turtles get the fragment free, Lord Dregg snatches it. Enraged, Tokka flies into space after him, forcing Dregg to take refuge in Mozar's destroyer. Before Tokka could do anything, Mozar fired meteor missiles into a nearby dwarf star before warping out, leaving Tokka to be seemingly vaporized by the resulting supernova.
It turns out that Tokka survived the supernova created by the Triceratons, and discovering that Chompy was not with her, set course for the Turtles' homeworld of Earth to reclaim him, knowing that Chompy was probably with the Turtles. Her approach is detected by the Earth Protection Force, who prepare to deal with her, thinking she's a threat to the planet, despite being assured by Utrom ambassador Bishop that Tokka means Earth no harm as she's only coming there for reasons they don't know about. However, General Griffen deems Tokka a threat, and on orders from the U.S. President, sends the EPF to deal with her, using commandeered Kraang weaponry to aid their fighters and ground troops. As Tokka deals with the EPF as they provoke her into attacking them when she's only looking for Chompy, the Turtles, especially Raphael, are able to get close enough to Tokka so Raphael can explain everything to her. Once Raphael explains that he only took Chompy in to care for him under the surmise that Tokka was dead, Tokka, realizing that Raph only took Chompy to protect him in case she was killed, stops her attacks, and rewards Raph with taking care of Chompy for her since he proved himself being able to raise him should anything happen to her. With Tokka having made peace with the Turtles and leaving Chompy in Raphael's care, she departs Earth to return to Magdomar without further problems.
Tokka appears to be a colossal turtle made of rocks and magma and had the third piece of the Heart of Darkness embedded in its spiked shell.
- Although female pronouns are used to describe Tokka in the show, head writer Brandon Auman described Tokka as being both male and female 
- Its design, and especially its method of flight, are likely homages to the kaiju Gamera; a monstrous turtle kaiju created by Daiei also known for protecting children.
- In other adaptations, Tokka had been depicted as the complimentary partner of Rahzar. In the 2012 series, Fishface instead is shown as the partner to Rahzar (the latest mutation of Chris Bradford) and Tokka is later featured in the fourth season as an independent character.
- This character alludes more to Terrorpin, the basis of Tokka's character.
- In "Tokka vs. the world", Channel 6 dubs her Terror-pin.