Moustache, sometimes abbreviated to Mous, (September 1799 – 11 March 1812)[nb 1] was a barbet who is reputed to have played a part in the French Revolutionary and Napoleonic Wars.

Whilst the regiment was encamped near Belbo the Austrians are said to have mounted a surprise night attack on the camp in stormy weather conditions.

It urged Marmont to provide an attack warning system by securing "a large quantity of dogs which can be made use of by posting them in front of your fortifications".

Both Cano and de Fivas say that whilst en route to Spinetta Marengo Moustache took part in a small engagement between a company of his regiment and some Austrians.

[4] De Fivas says that Moustache quickly pounced on the larger, stronger dog and fought with him for some time before a musket shot killed the pointer.

[4] Moustache deserted the grenadiers shortly after the French victory at Marengo, apparently because one of them attempted to chain him to a sentry box, and instead joined a company of mounted cuirassiers.

De Fivas states that Moustache went into battle with the cuirassiers and was present when the regimental standard bearer was surrounded by Austrian soldiers.

[9] It is at this point that de Fivas alleges that Moustache confronted the five or six remaining Austrians and was about to be bayoneted when the group was hit by a blast of artillery grapeshot.

[9][10] In recognition of this action Marshal Jean Lannes is reported to have ordered that Moustache's old collar be replaced with a copper medal on a piece of red ribbon.

[9] De Fivas states that this medal was engraved with the words "II perdit une jambe à la bataille d'Austerlitz, et sauva le drapeau de son régiment" on the front, and "Moustache, chien français : qu'il soit partout respecté et chéri comme un brave" on the reverse,[9] which translates to "He lost a leg at the Battle of Austerlitz and saved the regimental flag" and "Moustache, A French dog: Everywhere respected and cherished as a hero" respectively.

[12] De Fivas says that he attached himself to a unit of dragoons which he followed to Spain, taking part in two campaigns with them during which he would walk ahead of their column and bark warnings whenever he heard a noise.

[12] During a battle in the Sierra Morena mountain range in southern Spain Moustache is alleged to have led back to camp the horses of dragoons killed on the battlefield.

[5] After the allied victory over the French in the Peninsular War, it is alleged that the Spanish destroyed his gravestone and the Inquisition ordered his bones to be dug up and burned.