French Carabinier in pre 1810 bearskin and dark blue uniform & an Austrian Grenadier. The edict changing the carabineiers' uniform was passed on Christmas eve and was perhaps the quickest and most radical change in appearance of any fighting unit.
Kaiserliche-Königliche Grenadier Battalion (Hungarians). The Hungarian grenadier battalions (and the combined grenadier regiments) were some of the best units in the Austro-Hungarian army during the Napoleonic Wars, and were universally hated by their French adversaries.
Austrian Jager, Battalion Le Loup, 1800. The Austrians had nine dedicated Jager battalions. The jagers replaced the disbanded light infantry, but still retained their hechtgrau (pike-grey) uniforms and green crested helmets. The helmet was replaced as late as 1808 with the corsehut (Corsican hat). Only the first and second lines carried rifles, the third and fourth were armed with muskets.