Encino Man

When they find a frozen caveman in their back yard, two high school outcasts thaw him and introduce him to modern life while he in turn gets them to actually enjoy life.
High school misfits Stoney and Dave discover a long-frozen primeval man buried in their backyard. But the thawed-out Link—as the boys have named him—quickly becomes a wild card in the teens' already zany Southern California lives. After a shave and some new clothes, Link's presence at school makes the daily drudgery a lot more interesting.