When Sora is forced to play the game, different types of Magnum Loaders with different abilities appear as enemies trying to derezz Sora.
After the MCP gains control of the Heartless manufacturer, he creates several Heartless that exist in the Space Paranoids to attack Hollow Bastion, and some of them are Magnum Loaders. Back in the computer world, several of them attack Tron, but he is saved by Sora, Donald and Goofy.
A Magnum Loader's most prominent feature is the single, large wheel that comprises its lower body and provides its only means of movement. It is almost entirely black and is covered in red computer circuitry. Its head is long, sleek, and oval-shaped, and sports a jagged, red antenna on its top. Each of its short arms lead into grey, cylindrical hands tipped with conical, red spikes. Its glowing, yellow eyes are just barely visible in the front of its head. Its Heartless emblem is on its chest. During the Light Cycle games, several Magnum Loaders appear with circuitry that is a different color than the standard red, including gold, green, blue, and silver.
The Magnum Loader's name is a mistranslation of "Magna Roader", the same name as the Magna Roader from Final Fantasy VI, which is also a fast, unicycle enemy. Alternatively, "loader" can refer to a computer program that prepares others for commencement. "Magnum" is a Latin word that means "great".
Magnum Loaders appear both as an obstacle within the Light Cycle mini-game and as a normal enemy in various worlds. Within the mini-game, Magnum Loaders are incredibly fast, and each type of Magnum Loader has its own attack strategy. These creatures are encountered when Sora races on a Light Cycle. Only Red Magnum Loaders appear outside of the mini-game. They can be difficult to land a hit on due to their speed, but unlike the similarly-speedy Hot Rod, they are much more open to physical attacks, and can be easily brought down by hitting them with both spells and weapon strikes.