After the Daagon learned of their affiliation with the Utrom, they escorted the Turtles, Professor Honeycutt, April, and Casey to Hiidrala to request her consent retrieving the Black Hole Generator piece from her. Hiidrala quickly questioned whether or not they were worthy of claiming a device of such devastating power, and ask which of them was leader. When Leo steps forward, Hiidrala doubted him because of his youth, and again asks what makes him worthy. Leo makes his case giving her a brief history of the Turtles' success and witnessing the destruction of Earth, and Donatello asserted that they need the fragment to destroy it. Hiidrala though that idea was preposterous, as the Heart of Darkness is indestructible. However, she ultimately decided to allow the Turtles to take the fragment if the Cthugga, a creature who consents only those who are worthy to pass it, allows it.
Soon after, Armaggon hijacked the Ulixes and forced the heroes to lead him to the second piece of the Black Hole Generator. However, Armaggon did not heed Leo's warning that the Cthugga only allow those who are worthy to pass, and they were all subsequently chased away by it. After a narrow escape, the Daagon come to their rescue and apprehend Armaggon.
After they return to Hidralla's dwelling, she condemns Armaggon for his crimes and ridicules the heroes for failing to even stop him, let alone pass the test. As they ask for a second chance, Armaggon laughs, prompting Hiidrala to ask why. He says it is because his reinforcements have arrived. Lord Dregg and the Vreen then break into the dwelling, having already defeated a majority of Hiidrala's guards. Dregg threatened Hiidrala to hand over the Black Hole Generator piece, or he and his children will feast upon them all. Hiidrala tells him that he will have to get through her first, prompting the Turtles to assert the same, to Hiidrala's delight. During the fight, Hiidrala takes out a few Vreen before facing Dregg, who manages to momentarily blind her with his detachable hand and fires a missile from his chest at her. At the last second, Leo courageously jumped in front of it and took the missile to protect Hiidrala. Hiidrala, then out of anger, released a blood-curdling screech. Seconds later, the Cthugga responded to her call and came to her aid. It then devoured Dregg and Armaggon, leaving afterwards. The Vreen retreat having lost their hive mind in Dregg, rendering them unable to act individually.
Hiidrala then helped Leo to his feet and asks if he is okay, to which he say yes and asks her the same. She tells him she has him to thank for her being unharmed. She told the heroes that because they fought to protect the Daagon's kingdom, they have their gratitude and their actions validated their words. In turn, she gives them the piece. She revealed to them that the Cthugga was just a test and that they kept it hidden in the kingdom. She then told them that if they can really destroy the Heart of Darkness, calling it an infernal weapon, the Daagon honor them. Leo thanks her for that. Afterwards, the Turtles depart to find the third and final piece.
Being the Daagon sovereign, she is very wise and respected, and only grants the requests of those who prove themselves worthy of what they ask for. Honor is her priority, and she reward and respects those who risk their lives fighting by her side.
Because of her tentacle-like hair and arms, she is able to extend them to grab enemies and electrocute them, as she did with some of Lord Dregg's Vreen, and emit a blood-curdling screech to summon Cthugga to her aid to devour her enemies when she is enraged.
While her Daagon warriors are armed with tridents, swords, and lances to electrocute their enemies with, Hiidrala uses her arms and hair to lasso her enemies and electrocute them. Also, when enraged, she can emit a powerful, blood-curdling screech to summon Cthugga to her side.
Hiidrala's anatomy is quite complex and much different than others of her species. Her lower body is almost entirely tentacles while her upper body is relatively humanoid. She has an outer layer of small curved tentacles sprouting from her chest and larger ones lingering below her torso to simulate a dress. Her two arms are tentacles. She also has a layer of tentacles on her head to simulate long hair. Her eyes are completely blue, with her pupils being a slightly lighter shade. She has pattern of blue and pink stripes all around her body. Her face has light blue dots and has several red dots just above her brows, with an exclamation point pattern on her forehead. She also has long brow tentacles, a long, narrow nose, and sharp teeth.
- She seems to be inspired by Hydras, not the many-headed serpent in Greek mythology, but the genus of small, fresh-water animals.
- Much like Hiidrala, the Hydras have multiple tentacles and are generally sedentary or sessile, but do occasionally move quite readily.
- Biologists are especially interested in Hydra because of their regenerative ability – they appear not to age or die of old age.