Physically, a Utrom is a small and light creature. They have no hair and are usually a uniform pink color, but there are also variants of yellow and orange, purple and red. Their appearance is similar to that of a human brain. They have two eyes, a mouth with sharp teeth, and no visible nose, and a series of short tentacles beneath them. These tentacles serve as both hands and feet, as the Utrom can walk on them or use them to manipulate objects. However, most Utroms do not like to walk on their tentacles, and prefer to use some mechanical means of transportation, such as a human shaped exo-suit or a flight pad. Unless injured or sick, Utroms have a long life span, lasting centuries or millennia in Earth years. They have created very highly advanced technology, but how they achieved this given their physical form lacking almost any form of appendages remains a mystery. Utroms are usually very peaceful and not do interfere in the lives of others.
The history of Utroms, their common background with the Ninja Turtles and their escape from the Earth's is similar to their comic origins, although the Utroms landed their ship in medieval Japan instead of America in the 20th Century, and their stay on earth was enforced by the then still insufficient technological development of mankind.One thousand years ago, an Utrom ship was transporting the dangerous Utrom criminal Ch'rell. Unfortunately Ch'rell escaped and sabotaged the ship, causing it to crash on Earth. Landing in feudal Japan, the ship was damaged beyond repair and in the confusion Ch'rell escaped on Earth.
Unable to repair their ship, the Utroms decided to take advantage of their long lifespans (which allowed them to live for centuries, even millennia, of human time) and hide and peacefully wait for Humanity to advance and develop the technology they needed to go back home. In order To hide among the Humans, they developed human-shaped exosuits, However, one exosuit was captured by Ch'rell. To guard against the the renegade Ch'rell and his human underlings, the Foot Clan, they revealed themselves to a select few trustworthy humans who they named their Guardians. Centuries later, Hamato Yoshi, Splinter’s late master, would become an Utrom guardian. Ch'rell - now called "The Shredder" -hunted him down and killed him in an attempt to find the Utroms' location.
In the present day, the Utroms operate through the front company TCRI to conceal their true agenda. Though the company's official business is never revealed, unofficially it serves as a place to hide their advanced technology, such as the Transmat (a teleporter that can reach across the galaxy) and the Oracle Pod (a virtual reality chamber that replays historical records). T.C.R.I. is also responsible for the mutagen that transformed the Turtles, Splinter, and Leatherhead which was the fuel for their Transmat. This would eventually culminate in the Foot invasion of the TCRI headquarters in New York shortly after the Turtles infiltrated the building in search of Master Splinter. The Utroms succeeded in returning home.
The Utroms later return to help the Turtles in their battle against The Utrom Shredder. Thirty seconds before the The Shredder's ship blew up, they put the ship in a stasis field and used the Transmat to transport everyone out. On their homeworld, The Utrom Shredder—now identified as the Utrom Ch'rell—stood trial and was sent to exile on an icy asteroid prison, Mor Gal Tal.
In the dystopian future seen in Same As It Never Was, amongst The Utrom Shredder's soldiers are enslaved, and apparently somewhat zombified, Utroms. Some of these zombie Utroms are fitted into giant, winged, mechanic-like exo-suits, and are known as Utrominators. During the future seen in Fast Forward, the Utroms were apparently among the aliens involved in the Pan-Galactic Alliance.
- "The Search for Splinter, Part 2"
- "Secret Origins, Part 1"
- "Secret Origins, Part 2"
- "Secret Origins, Part 3"
- "What a Croc!"
- "Worlds Collide, Part 1"
- "Same As It Never Was"
- "Exodus, Part 2"
- "Aliens Among Us"
- "A Tale of Master Yoshi"
- "Bishop to Knight"
- "The Journal"
- "Wedding Bells and Bytes"
- Mortu: Mortu was the captain of the Utrom ship that crashed on Earth. After the crash, he remained the field-leader of the marooned Utroms, and worked as their liaison to the Humans. In the modern day, this makes him CEO of the front company TCRI. His name is "Utrom" backwards.
- Council of Three: These three otherwise unnamed Utroms are the highest leaders of the Utroms on Earth. Although it is not explicitly stated, it is strongly implied that these are the same brain-navigators that Captain Mortu took orders from one thousand years ago aboard their ill-fated star ship.
- Ch’rell: The most ruthless criminal the universe has known. Ch'rell dreams of galactic domination, and wants vengeance against the Utroms for imprisoning him and denying him his dreams by building an army and attacking their homeworld. This is the true identity of The Utrom Shredder in the 2003 TV series. Prior to his arrival on Earth, he was responsible for the deaths of millions of people in his attempts at universal domination.
- Krang: A Utrom by the same name as the villain from the 1987 cartoon makes a brief cameo appearance in the episode Secret Origins, Part 2. He mentions how he hates walking on his tentacles.
- Abraham Lincoln: The 16th president of the United States is seen to secretly be an Utrom in an interstitial.
- Utrom High Council: The Utrom High Council is a collective body on the Utrom homeworld who appear to be the governing body of the planet and the navigators on the stranded ship. The judgements of Utrom criminals such as Ch'rell are carried out on the Utrom homeworld by the Utrom High Council. Not much is known, but they are responsible for the Utrom Shredder's banishment to a frozen asteroid.
- Utrominators: The Utrominator exo-suit is what was given to the Utroms when Ch'rell enslaved them in "Same as it Never Was".