Walk Like a Man (1987)

As a baby, Bobo gets separated from his family during a camping trip. After being raised by wild dogs for twenty years, Bobo is discovered by animal researcher Penny, who brings him back to his family and attempts to teach Bobo how to readjust to life with humans. While his mother is overjoyed to see him again, Bobo's older brother Henry is more worried about losing his share of the inheritance. As Bobo progresses with Penny's lessons, Henry plots to have him eliminated.