I agree, it's a bunch of stuck shed. About 3 or so months ago I adopted a then 10 month old male from a family who couldn't afford to take care of him, and he never had any
UVB light at all; I have no idea what his basking light was or if his temps were ever correct, he had severe MBD, and was fed only mealworms. And what I first noticed when I saw him was his skin/scales and his color. He was almost a year old and he looked like he hadn't shed. Ever. He had a build-up of dull, lifeless scales and skin that made him look 100 years old.
I had no experience with this at all, so I did some research and found out that beardies who are not provided proper lighting, temperatures, diet, and nutritional supplements actually stop shedding because they're not growing properly. As a result their skin ends up like his. Your beardie doesn't look nearly as bad, but he definitely needs to shed, and he will after getting appropriate care from you. My boy finally did a full body shed last month, but he did it literally one little patch at a time, and it took all month. He had retained shed or "old shed" similar to your dragon's tail on his head. It just took a month or so of proper lighting, diet, 10 minute soaks every other day, and growth to get it going.
Now your guy obviously had a tail nip, probably from being housed with another beardie, so you'll want to be sure to closely watch the end of his tail as well as the area above the stuck shed. If the end of his tail where the nip is starts to look at all infected, or starts to turn black and that blackness starts to move up his tail even a little bit, you need to get him to an experienced reptile vet ASAP, because that's tail rot, and it's an infection that will continue to spread up his tail, killing the tissue behind it, and eventually making him extremely sick. His nip looks pretty good so it's most likely not going to be an issue, but just be aware of it.
The only harm the stuck shed can bring is if it's all the way around the diameter of his tail, and it starts to cut off the circulation in his tail below it, causing that area to become necrotic, turn black, and die. Again, I highly doubt he'll have that issue at all, just be aware of it. It should eventually just come off itself as he sheds.