To dream of a caveman represents you or someone else that is totally preoccupied with surviving or living in the moment.
Negatively, a caveman may reflect a constant state of fear of serious troubles returning. To much focus on short term living and not focusing on long term living. Dangerously living in the moment.
Example: A man dreamed of being with an invincible club and invincible penis. In waking life she was experiencing uncontrollable sexual desires after having woken up from a catatonic “sleeping disease” and being put on strong medication. The symbolism may have reflected his fear of not enjoying every last minute of his life that he could having sex or being risky before his disease returned.