Mokele' (Peter Smith, formerly Portia) is a member of the Tigers and C.O.R.E.. He has the unusual ability of serial shapeshifting—he can assume various animal forms, but he can't reach most of them directly, having to shift into another form first. This limitation seems to be mass related, that is, he can only change his mass so much with each shift. For instance, to become a dragon, he has to change first into a panther, then a bear, then a rhinoceros, and finally the dragon form, which was described as having "maybe the same mass as an elephant."
This ability might be mystical in nature, since he is able to assume the shape of a mystical animal like a dragon. Furthermore, the transformation goes deeper than the mere appearance of a dragon, because the venom he produces is considered very valuable by the Mystical Arts teachers. The Mystical Arts department pays a thousand U.S. dollars a fluid ounce (29.57 ml) for that venom.
It was revealed that not only is he a female-to-male "changeling" (and very unhappy about it), but also that he's fully aware of Team Kimba's situation in that regard. That's explained by him being a Poe Cottage resident. He's a junior by January 2007.