After these tanks were phased out in favor of the Mammoth Mk. II Walkers, the Forgotten managed to acquire some units for their own use. Others were abandoned with surplus field bases; some of these abandoned vehicles were still serviceable by the Second Tiberium War.
The Mammoth may self-repair to 50% health. They are encountered in the sixth Nod mission, used by the Forgotten. Tanks with 4% health (or lower) do not self-repair and may require aid from a third party for the self-repair to take affect. Interestingly, these circumstances were also present during the First Tiberium War.
Several abandoned models were also used by Nod in testing their Banshee fighters. Mammoths may also be used by GDI in the final GDI mission if recovered from the abandoned base.
The Mammoth uses the same missiles as the Mammoth Mk. II, which can attack air targets. The Mammoth's default guns are the same as the ones used by elite Tick tanks.
Mammoths may also be obtained as a random unit from Crates in skirmish games (though it is very rare and may require the tech level to be set to the highest setting).