He was in all of those vlogs because he was doing a photo book about the UFC called "Into the Cage". For like 2 years he went backstage and was taking pics and shit for the book.
It's actually pretty great. Some really, really good shots in there. I was surprised to be honest. It focuses 99% on modern day UFC, is very pro Dana/Zuffa biased, and doesn't really tell the story of the early UFC accurately. It's not a great historic account on MMA history, but it does have some cool stories on the old school guys. Like, the Tooth tracked down Tank at a bar in HB and sat and drank with him and his dad for 2 straight nights. there's pics of them in the bar (Tank/Tooth/Tank's Dad), and stories from Tank, that are very cool and I hadn't read them anywhere else.
However, that is not why I bought the book. Although there are cool things inside text wise, I just wanted the photos. He is a talented photog for sure. Some really great stuff in it. I got it online for $10 in mint shape. Would recommend at that price for sure. Not at the listing price, though.
I really want to get Nagao Susumu's 2 photo books, especially From Vale Tudo To MMA. That one looks awesome. Another MMA photo book I own called Fighter by Reed Krakoff is ok. Just a bunch of pics of UFC fighters standing in front of backdrops. Kinda lame but I got it online for $4... The list price on the jacket of the book was $45, lol. Hipster douche
Anyway TLDR: Tooth put out a cool book with good photos.