From Halopedia, the Halo wiki
The "mammoth" was a species discovered on Installation 00 by the participants of Operation: FAR STORM. While superficially similar to an extinct genus of proboscidians native to Earth, they differed by having white fur and four tusks. The animals stood five meters tall, and were able to carry a number of people, including armoured Spartans and Sangheili, controlled by pheromones by the Monitor of the installation, 000 Tragic Solitude.
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