The XM-157 Drake was an 8-ton 8x8 amphibious craft developed by General Motors for the US Army. The 45-foot long craft weighed 8 tons and was powered by two 5.0-liter engines.
WWII Ford GPA 'Seep' - photos
Amphibious excavator poling itself downriver - GIF
Coastal Research Amphibious Buggy - video
Amphibious craft powered by a Vespa scooter - GIF
Amphibious motor coach that doubles as a yacht - video
1960s amphibious scooter - GIF