Jaguar

In Mesoamerica, the Olmec—an early and influential culture of the Gulf Coast region roughly contemporaneous with the Chavín—developed a distinct "were-jaguar" motif of sculptures and figurines showing stylised jaguars or humans with jaguar characteristics. In the later Maya civilization, the jaguar was believed to facilitate communication between the living and the dead and to protect the royal household.

Monica reiterated the above emphasized point here.

Phix, in her enigmatic way, gave Monica a huge clue about her own nature in the following strip.

In this strip and the following one, Monica comes to the conclusion that the Jaguar Temples were created as mechanisms for communicating with the dead. She subsequently confirms this in a conversation with Bud (see the linked strip and the several following.)

On October 3, 2012, Monica exits her body in a form of astral projection and we discover that she is the Jaguar Girl. What ramifications this has for future plot developments remains to be seen.