The fruit is a light orange color, and looks similar to that of the durian fruit. It is spawned by the Tree of Might after enough energy and life force is absorbed through the tree's roots, but like a regular plant, it needs a suitable atmosphere to survive (such as Earth's or Namek's). As such, large amounts of energy are required to supply the fruit's growth and the tree essentially sucks the life out of the planet the seed was planted on. Despite all this, the Tree of Might is not truly evil but simply requires such a massive amount of energy to grow. Few, if any planets can sustain it without dying. King Kai mentions that only Gods are meant to eat the fruits; in the FUNimation dub, King Kai says that the fruit was originally meant to feed the Eternal Dragons (Shenron, Porunga, etc.).
This fruit gives whomever consumes it a massive power increase, and squeezed fruit from the Tree of Might would make a powerful energy drink. Amond mentions that with the use of the Tree of Might's fruits, they might even be able to defeat even Frieza. Turles eats this fruit during his battle with Goku and quickly gains a strong advantage, with his power level being increased by more than 15x its original level.  Goku attempts to attack Turles with repeated Kaio-ken attacks, but even this is nowhere near enough to bring the evil Saiyan down. Goku eventually spawns a Spirit Bomb after absorbing the energy of the tree (as the tree is essentially a living thing, energy can be gathered from it for a Spirit Bomb), and successfully kills Turles and the tree along with him.
Eating the fruit immediately increases the user's muscle mass dramatically, the user's body then quickly recedes back to its normal shape. It is unknown whether or not Turles' body would have been permanently bulked up had he eaten all the Tree of Might fruit on Earth.
When playing as Turles in the Budokai Tenkaichi series, before battle, he will be seen holding a piece of the fruit. He can also eat a piece of fruit during battles which makes him instantly go to MAX Power. It gives him an increase in strength, speed, ki, and defense for a limited time (further shortened if he uses a Blast 1, Blast 2, or his Ultimate Blast), as well as regenerate 1 health bar. The fruit of the Tree of Might also makes a similar appearance in Dragon Ball: Raging Blast 2.
In Dragon Ball Z: Battle of Z, Fruit of the Tree of Might is an item that increases all abilities.
In Dragon Ball Xenoverse 2, it appears as a Super Skill used by Turles who will teach it to the Future Warrior (Xenoverse 2) during their training under him. In Xenoverse 2, in addition to acting as a power-up, it also allows the user to perform a melee attack after consuming it via additional input, which causes the user to Z Vanish and attack the opponent with a powerful punch strike. However the user is vulnerable when consuming it and the follow-up melee attack can miss. Additionally, while training under Lord Slug, the Future Warrior learns that Slug is planning on using a sparing session between Turles and the Future Warrior to steal some of the Fruit of the Tree of Might as Lord Slug has only allied himself with Turles out of convenience and eventually plans to betray him. However Lord Slug fails to steal the fruit, though claims he will acquire it one day.
During the main story, Turles has Towa use her scientific knowledge to enhance the Fruit. Towa exposes the fruit to the environment of Demon Realm, creating a Demon Realm-enhanced strain that emits dark energy and causes consumers to take on Villainous Mode. She gives this fruit to Turles and Lord Slug. Turles later uses this fruit to empower Jeice and Burter while they are fighting the Future Warrior and Goku, however Burter is killed like he was historically and Jeice is later killed while fighting alongside Captain Ginyu in Xeno Trunks' body. After Turles gives the fruit to Burter and Jeice, Elder Kai recognizes it as the Fruit of the Tree of Might. Unaware that it has been altered by Towa, Elder Kai states that normally only divine beings such as Gods of Creation (this also presumably includes the Kais, Gods of Destruction, Angels, and Zen-Oh as they all are divine beings) like Elder Kai and Chronoa are allowed to eat the holy fruit which takes the energy of an entire planet to produce. Elder Kai is shown to be upset by Turles' abuse of the fruit and states the criminal must be punished for his blasphemy and using the fruit to alter history. Despite this, the 2nd Future Warrior and other Time Patrollers are apparently permitted to use the Fruit of the Tree of Might Super Skill, presumably due to them being under the Supreme Kai of Time's authority. It is later revealed that Turles plans to steal the Namekian Dragon Balls and use them to wish for Immortality, believing that with an immortal body and the Fruit of the Tree of Might he can become powerful enough to defeat Kakarot, Frieza, the Time Breakers, and Lord Slug allowing him to conquer the Universe. However Lord Slug reveals that he too desires immortality and plans to conquer the Universe for himself. When the Future Warrior stops Turles and Lord Slug from stealing the Namekian Dragon Balls, Turles and Lord Slug decide to put aside their differences to deal with the Time Patroller and consume the enhanced fruit to power up, granting them Villainous Mode. However unbeknownst to Turles or Slug, Towa had tampered with the fruit, causing their bodies to swell with dark energy, which causes Turles to speculate that Towa had tampered with the fruit. Towa and Mira soon appear and Towa reveals she had altered the fruit to test out a new spell that shaves off life to grant one greater power. This causes Turles and Slug to take an incomplete Supervillain state, that increases their power even further, though at the cost of decreasing their natural life span. However Turles and Slug are thrilled by their newfound power, with both believing that Towa has made a grave miscalculation. Xeno Trunks arrives and tells the original Future Warrior to chase after Towa and Mira, while he aids the 2nd Future Warrior in defeating Turles and Slug. Turles and Slug attempt to kill Turles with a Darkness Blaster and Sudden Storm Combined Energy Wave only to for it to be countered by Xeno Trunks and the Warrior combining Trunk's Burning Attack with the Future Warrior's Energy wave which defeats the two villains. However the enhanced fruit appears in Parallel Quest 17: "Ginyu and the Fruit" where Turles gives it to the entire Ginyu Force forcing the Time Patrol to defeat the enhanced Ginyu Force members. If the Ginyu Force is defeated within 10 minutes, then Turles will flee and the Time Patrol will give chase. They find Turles showing the Fruit to the Saiyan Prince Vegeta (back when he was a villain) who eagerly consumes the fruit alongside Turles, causing them to both take on Villainous Mode and attack the Time Patrol, only to be defeated. Additionally the Tree of Might appears as a stage with fruit growing on it. While this stage plays no role in the main story, it does appear during Turles and Lord Slug's training.
In Dragon Ball Fusions, Fruit of the Tree of Might is a Special Move which can be used by Turles who can learn it after reaching Level 100. It can also be used by his EX-Fusion Tutz after reaching Level 100 as well. If Tekka performs EX-Fusion with Turles their fusion can learn it after reaching Level 100 as well.
"The Demon Realm has amplified its effects. Whoever eats of the fruit of the Tree of Might will gain incredible power beyond compare."
— Towa's description of Fruit of the Tree of Might (Demon Realm)
Fruit of the Tree of Might (Demon Realm) - The Demon Realm is capable of amplifying the effects of the Tree of Might's fruit. This was discovered by Turles and Towa in Xenoverse 2 when Turles requested that Towa get some of the fruit for him. Anyone who eats this amplified fruit will gain power beyond compare. It is implied by Turles that Towa modifies the Fruit, so that it causes the consumer to take on the Villainous Mode state after consuming it and allows Towa to power them up further by shaving of some of the consumer's life force to grant them an unfinished version of the Supervillain state.