I found this on BJJ Eastern Europe and thought it was worth sharing.
Very long, but very funny (and true) list, and I'm sure anybody who trains BJJ/Judo will agree!

The Craftsman – You roll with the guy for 5 minutes and get tapped 5 times. The guy is good but even he doesn’t know exactly what he’s doing. He just sees something and tries for it because he knows the joint doesn’t bend that way. You’re learning moves together as he taps you out.

Mr. Goodwrench – This guy just tools you. Not for any negative reason, but just because he knows his stuff. If you go hard, he taps you for being over-aggressive, if you go light he taps you for not pressuring and thus giving up position. If you are in between he just controls you and sweeps or reverses you at will. When you look at him in disbelief he just looks at you like “What… did time run out?”

The Pretzel – Every move you’ve ever practiced becomes difficult because this guy can get into positions that would make a pretzel cringe.

The Risk Taker – This guy does such unexpected, often ridiculous stuff that ends up working because you weren’t expecting a back handspring guard pass or head stand to armbar from halfguard, etc.

The Mailman – This guy takes the same route for 2 years and gets caught in the same submissions or set-ups every time. He never changes his guard passing routes, and becomes totally predictable.

The “just got back from Rio” Guy – This guy is good, and since he just spent 6 months training his ass off in Rio he is super smooth. But he wants to make his home school into the place he trained in Rio. He shakes hands with everyone in the room before sitting down to stretch asking “tudo bem?” He answer’s his cell phone “fala”. He speaks in portuguese with the instructor when he talks about how to beat someone without wanting them to know it. He counts in Portuguese. If you want to get on his good side and get him to show you some cool shit he learned down south, just ask him about his time in Rio, he will be more than happy to tell you about it. Everyone who goes to Brasil is guilty of this when they get back.