Battle Tops

It moves too fast to touch, yet it stays in one place. It's so stable, military jets use them to stabilize themselves. And it's so cheap and plentiful, every toy store's bargain bin has them. It's the gyroscope, also known as the top. And in the world of fiction, there are some who decide to weaponize them. There are two different ways to go about this:

The first is to spin some tops, then throw them. They will either throw them at the opponent, counting on the impact force plus it being a rapidly-spinning object; or they will throw them at the ground, where they will either stay in place and deal damage to anyone who touches them or drift around along the ground, making it difficult for opponents to maneuver around. Tops differ from other ground-based obstacles in that they trace irregular paths and will move faster when they touch each other. In rare instances, it's not so much that it spins as much as the spinning creates something more dangerous, such as whirlwinds or lightning. In these cases, a top is the optimum shape for something to spin around real fast without any additional input of energy or anything to hold on to the object.

The other approach is to actually spin themselves like a top as an attack. This is distinguished from ordinary Everything's Better with Spinning in that the fighters are either shaped like a top by default or can convert themselves into a top-like shape, with a point at the bottom. They follow top-like movements and may have a long stick over their heads. May overlap with Spin to Deflect Stuff in this sense.

Whether they deploy tops or spin like one, there is always the option to make them even more painful to touch by modifications, such as spikes or blades along the rim to create a makeshift and portable buzz saw, using durable materials to be reused again and again, or to tweak the weight for maximum kinetic force.

In any case, expect these characters to have very good balance.

Subtrope of Improbable Weapon User and Everything's Better with Spinning. When the axis of rotation is turned parallel to the ground and a string thrown in, it's Killer Yoyo.

Examples of Battle Tops include:

Anime and Manga

This is the premise of Beyblade.
In Hunter X Hunter, Gido tosses tops infused with nen (life force). When hit, the main character remarks that they hit like a sledgehammer. If the opponent gets too close, Gido can then spin like a top.
Shippo in Inuyasha has an arsenal of tops.
Giant mecha Voltes V has the Ultraelectromagnetic Top attack. It has hard blades, comes in twos, manipulated by the giant robot using its belt, and are colored RED.
In One Piece, Captain Buggy's First Mate uses spinning tops in one of his attacks.
In Battle Angel Alita, motorball second league champion "Caligula" Armburst has an ability to transform into one.
In Sailor Moon, Tuxedo Mask inexplicably goes through a brief spinning top phase; Presumably to keep with the holiday theme of the movie, during the Sailor Moon S movie, instead of employing his deadly throwing-knife roses, Tuxedo Mask launches a spinning top at the face of one of Princess Snow Kaguya's more unfortunate Snow Dancers.

Comic Books

The weapon of choice for The Flash villain The Top.

Literature

The Laughing Larrys from James Alan Gardner's novel "Hunted". A spinning spherical robot that shoots razor-sharp flechettes in all directions. It makes a laughing noise while it flays you alive.

Live Action TV

Kamen Rider Yuki, Big Bad of the third Kamen Rider Den-O film, uses wooden exploding toy tops as one of his weapons. As a necromancer, he also uses them to ressurect an army of Imagin for the final battle.
Kamen Rider Meteor from Kamen Rider Fourze uses his Meteor Storm Switch as this for his finisher.

Tabletop Games

There was a board game called Battling Tops back in the 60s and 70s. The tops were spun up to speed using threads wrapped around them.

Video Games

Top Man in Mega Man 3 and his counterpart, TopMan.EXE in the Mega Man Battle Network series. Both can spin or toss tops, although Mega Man is only able to copy the spinning. There's also the second stage of the battle with Elpizo in Mega Man Zero 2, where one of his attacks involves a flying, spiked, golden top.
ROB from Super Smash Bros. Brawl can charge up and launch a top from Gyromite. It stays in place and damages any other player who touches it. ROB can move over and pick it back up to throw it again. The charge time determines how long the top remains spinning.
The Legend of Zelda Majoras Mask: In its final form, Majora's Incarnation, the titular mask attacks with a pair of whip-like appendages and razor studded spinning tops.
- The Spinner in The Legend of Zelda Twilight Princess is a top-based battle vehicle.
Metroid Prime 2: Echoes had the Quad drones as well as the Quadraxis boss battle, which could curl up into spinning top shapes. The former could only be stopped by bashing into them using the Boost Ball.
The Pokémon Hitmontop is based on a combination of a spinning top (hence the name) and capoiera martial arts. A mini-game in Pokémon Stadium 2 is a battle between four Hitmontops with the goal of knocking the others out of the ring.
In Super Mario Galaxy, one of the bosses, Topmaniac, IS a top. He is the leader of the Topmen, smaller sentient tops. The latter return in Super Mario Galaxy 2.
In Super Monkey Ball 2, an early stage is called "Spinning Top." The sole obstacle in this stage is a humongous top would knock the monkey completely off the stage if touched due to its spinning. The goal ring is located dangerously close to where it spins, and 1-up yielding bananas are hung from its edge.

Western Animation

The Spinning Tops of Doom in Kim Possible.
In one episode of Superman: The Animated Series, Toyman unleashes a gigantic top that generates electric fields against Superman.
In the Phineas and Ferb episode "Phineas And Ferb-Busters!" the kids play a 4-person game of "Battling Tops of Doom" (possibly as a Shout-Out to the Kim Possible example). The tops are something like 20' tall, and the players ride inside them.
Chanukkah Zombie's space fighter from Futurama shoots dreidels.