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.
"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.