The OZ-13MS Gundam Epyon is a mobile suit introduced in Mobile Suit Gundam Wing. Originally piloted by Heero Yuy, it was later given to Zechs Merquise.

Based on data from the OZ-00MS Tallgeese and the other Gundams, the Gundam Epyon was created by Treize Khushrenada while he was placed under confinement by the Romefeller Foundation. In keeping with Treize's philosophy, the Epyon eschews cowardly long-range weapons in favor of chivalrous close combat. However, when the suit becomes a part of White Fang, a pair of Vulcan guns are added to the head. Its main weapons are a segmented, whip-like heat rod mounted on a shield and a powerful beam sword whose energy is supplied by a direct connection to the Epyon's generator.

Treize also installed a modified version of the Zero System known as Epyon System in the cockpit, making this suit a powerful opponent. The Epyon can also transform into a "mobile armor" mode for high-speed flight and cruising in space. It resembles a mythological dragon in this mode, however, its primary weapons are inaccessible save for the Epyon Claws which are also used as landing gear in this form.

Gundam Epyon EW is Hajime Katoki's redesign of Epyon in a similar fashion to other EW version of the first five Gundams and included in New Mobile Report Gundam Wing: Frozen Teardrop as well as Mobile Suit Gundam Wing Endless Waltz: Glory of the Losers. It is later given additional equipment known as 'Sturm Und Drang' that can be used for both defense and offense.