Possible Clues:

• Root beer brand
• Root beer brand that "has bite"
• Big name in root beer
• Dad's rival
• The 'Famous Olde Tyme Root Beer'
• Coca-Cola root beer brand
• ___ Famous Old Tyme Root Beer
• Soft drink company formed in New Orleans in 1890
• Caffeinated root beer brand
• Famous Olde Tyme brand