The Mammoth tank, also known as Mammoth Mk. I, is a GDI heavy tank that appears in Tiberian Sun and Firestorm.

After the First Tiberium War, these tanks were phased out of service in favor of the new Mammoth Mk. II walkers. Some of them were used as targets for weapons testing by GDI and Nod. The Forgotten also used several of these vehicles in their arsenal.

The Mammoth tank is armed with a pair of powerful cannons and anti-air missiles. It is also extremely durable and also has the ability to self-repair to 50% health (though it cannot do so if its health is less than 4%). Its greatest weakness is its very slow speed, which can leave it vulnerable to enemy artillery and stationary defenses.