Sharquoi
From Halopedia, the Halo wiki
Template:Diagramneeded In the Conversations from the Universe booklet found in Halo 2: Limited Collecter's Edition, an Elite refers to something called the Sharquoi. This has been assumed to be another Covenant race. In a deleted scene, a mural can be seen showcasing the Covenant races including a very large creature assumed to be a Sharquoi. Because of its similarity with the Drinol, many speculate they are the same.
From a Bungie Weekly What's Update:
Q: What's a Sharquoi?
A: Very freaking dangerous.
Recently, Frankie has talked about playing Halo 3, and fighting Grunts and "something larger than a Grunt," supporting the idea that the Sharquoi will be seen in Halo 3.