Tabuu is a blue matrix-like humanoid who became recently enemies with Master Hand.
He was created in 1,242,342,754 BCE. Tabuu was born a millennium before Unicron. Tabuu was created by mixing the DNA of Thanos and Chuck Norriseegee in 1,242,342,754 CE and sending the mixed DNA back in time, which makes him kinda a demigod (This doesn't mean he is invincible, however).
Tabuu has thirteen different attacks; all of which can be explained here:
His thirteen moves
His first move; Shark Blade: He turns into a giant blade resembling an ocean shark and charges them.
His second move; Diving Slash: He appears high and transforms into an energy blade and dives to the surface and rams/stabs the enemy.
His third move; Golden Bracket: He transforms into a cage of energy, resembling two golden brackets, and flies and captures his opposing enemy, and then plows on the front of the floor.
His fourth move; Chain of Light: He creates a golden chain and throws it in order to catch his opponent.
His fifth move; Electrical Shield: The purple sphere inside his torso splits into several fragments, which fly in circles around him for a short time while emitting electricity. This attack has a decent range, but leaves Tabuu wide open for projectile weapons. It somewhat resembles an atom, with Tabuu being the nucleus and his fragmented energy core being electrons.
His sixth move; Rapid Chop: He teleports behind his opponent and repeatedly chops the enemy karate style and same for the area in front of him; so he could be slashing more than one person. This move can easily catch and juggle his opponents, though has less range than other attacks.
His seventh move; Pinpoint Explosion: From one side of his foe, he preforms a pointing gesture. Five locations along a line leading to his opponent's current location will flash golden once and explode after about two seconds.
His eighth move; Ghost Projection: Tabuu splits himself in half and shoots out many ghost images of himself in every direction, which explode after achieving a certain distance. They explode when they make contact with the ground, so just sidestep the projection itself. The ghost images can also be destroyed, preferably by projectiles.
His ninth move; Dragon Cannon. He grabs out a giant cannon resembling a dragon that also acts as kind of a hover-motorcycle and blasts a powerful beam of dark energy from his cannon.
His tenth move; Bullet Rain. He opens his palm and shoots energy bullets from his fingers acting as raining bullets.
His eleventh move; Shuriken Boomerang. He throws out a boomerang that also acts a shuriken towards the opponent.
His twelfth move; Laser eyes: Tabuu grows so giant that his foe goes only up to about his chin and Tabuu starts shooting lasers out of his eyes. This is really the only time he gets giant. He's matrix-like anyways so yeah.
His thirteenth and final-finishing move; Off-Waves: He spreads out his infamous wings and OHKOs the enemy.