Laawaris (1981)

Left in the care of an alcoholic Gangu Ganpat (Shreeram Lagoo), young Heera, who named himself after a stray dog, wrestles with life in his young age. Years later, now a young man (Amitabh Bachchan), he works for Mahendar Singh (Ranjeet) and is in love with Mohini (Zeenat Aman), who will not have anything to do with him due to his lack of ancestry. Heera is now determined to find out who his parents are, and the only one who can help him is the elusive, alcohol-induced and incoherent Gangu Ganpat.