What is the name of this movie?

It was from either the 80s or 90s what i remember is very vague. a man inherits a house and moves in with his girlfriend and his friend they end up digging up his great grand something father but hes not really dead because of a magic crystal skull. heaps of crazy stuff happens i also remember a dodo bird and an evil red headed cowboy and some bikers. It was very weird but it is driving me crazy. Please help.