The tags on the bottom of your tongue are fimbriated folds, also normal and certainly not hazardous to your health. I have em. They look almost devilish don't they?
Most often, the oral cavity and tongue get wierd things happening. Makes sense since lots of different chemical reactions from the food you eat. Bumps on the back of the tongue are normal.
Here is a link that may help:
There are many other links that that one above. I had a sore a few months ago that was inside my lower lip and lasted 12 hours (half a day). It was my paranoid stage when I thought I was suffering from oral HPV.