My friend has several abnormally large bumps on the back of her tongue, no pain, sore throat, and sniffles. what could it be?

Enlarged taste buds?: Could be enlarged taste buds or normal tongue anatomy. Hard to say. If in doubt, I would see either an ENT Dr. or a dentist.

Normal: These are the circumvallate papillae. They located on the back of the tongue behind the smaller papillae. They are usually 1-2 mm in diameter and most people have between 8-12. They tend to be more apparent on teens and adults then young children.

Normal anatomy: Circumvallate papillae are they large taste buds on the tongue. They are a normal anatomical structures of your tongue and do not go away. Hope it helps.

Probably normal: Likely normal. If you're worried, see an oral surgeon for examination