Mario Tornado

The Mario Tornado is the name given to Mario's Down Special in the first two installments of the Super Smash Bros. series. In Brawl, his Down Special was replaced, and Mario Tornado became his Down Aerial instead. The move involves him rotating rapidly with his fists outstretched. It is a multi-hit attack, and the last hit can spike in the original SSB64. This attack's knockback was always the same in the original Super Smash Bros., regardless of the enemy's damage. However in Super Smash Bros. Melee the knockback increased with the opponent's damage. By pressing the Special Attack button rapidly, Mario would rise up in the air slightly and give him a slight recovery chance.

Dr. Tornado
Dr. Tornado is one of Dr. Mario's special attacks in the game Super Smash Bros. Melee. The attack is executed by pressing Down + B. Dr. Tornado has the same effect as the Mario Tornado, except that it is a little stronger. The special attack traps the victim into a tornado, punches them constantly, and then smashes them up into the air when the move is done. The attack can also very lightly pull someone near into the Tornado. Unlike Mario Tornado, Dr. Tornado throws them in a random direction, rather than straight up. Dr. Mario is able to hover in the air when using this attack, by holding the B Button while using it. Also, Dr. Mario doesn't yell "Yahoo!" or "Yee-haw!" when performing the attack, unlike Mario, but for some reason, the "Yee-haw!" effect can still be heard as one of Dr. Mario's sounds in the Sound Test menu and when he uses his back to a tornado.

In Super Smash Bros. Brawl
In Super Smash Bros. Brawl, Mario's Down B has been replaced with F.L.U.D.D.. In the DOJO!! update revealing this change, a screenshot of the Mario Tornado is shown with the accompanying caption: "He still seems to have this move, though. Eh? Is it a normal attack?!" The E For All demo eventually revealed that the Mario Tornado was, in fact, merged with Mario's old down aerial move. The attack is quicker, but the damage is actually unchanged. In fact, it has been discovered to be an effective KO move when used in midair, if the opponent is hit at the very end of the tornado. Because of it being an aerial attack, it does not affect Mario's falling speed, but it can slightly stop his momentum when he is knocked into the air. As a Down Aerial, one must be careful not to fast-fall while using it. It is also the only Down B to be replaced by another move.

Origin
Mario has used spinning as a main attack method ever since Super Mario Bros. 3, where if he was Raccoon Mario, he could spin and use his tail as a short ranged melee attack. The Mario Tornado is probably based on the Spin Jump that originated in Super Mario World. When the player presses the A button in that game, Mario will spin around and jump, which would bounce harmlessly off certain enemies, kill some that usually require more than one hit and break certain blocks (if he is large).

Additionally, if he had his Cape he would be able to spin his cape around which could damage certain enemies and break blocks, and if Mario did the Spin Jump while running with the cape, he would fly upwards while spinning(depending on how long the player held down the button). When equipped with a Fire Flower, he would shoot fireballs while spinning. This move was also used to dismount Yoshi. However, unlike normal flight, he can't glide afterwards. Spinning has been one of Mario's signature moves since then. In Super Mario 64, Mario could spin similarly to Mario Tornado, but it was used to slow down his descent instead of jumping, and could not be achieved under normal circumstances. Mario was also capable of spinning rapidly in Super Mario Sunshine, although this game post-dates the first appearance of the Mario Tornado in Super Smash Bros.

In a more recent game, Super Mario Galaxy, Mario also has a spinning attack similar to this; it also gives him a short boost in height. The spin jump retains the same use for Super Mario Galaxy 2. More recently, the Spin Jump from Super Mario World has reappeared in New Super Mario Bros. Wii. Many of its functions, such as breaking blocks and defeating stronger enemies, have been replaced with the Ground Pound, and instead, spinning is used to clear away fog, activate certain stage elements and gain more height when landing on an enemy.

Trivia

 * Technically speaking, this move is the only Special Move that can be used by a generic enemy, namely the Yellow Alloy, although at the time, Yellow Alloy is copying Mario's Brawl moveset as opposed to his Melee moveset, in which the Mario Tornado was still a Special Move. It is not, however, the only Special Move that can be used by any non-playable character, since Giga Bowser shares his moveset with Bowser.