Just for fun: Tank archetypes!

[Aurelinaus]

Don't Have a name for these tanks but they plague df like cockroaches. They're almost always a Tome hero and VIT maxed. They're going to MT due to ilvl and hp, are going to explain the fight and/or how to your role to you. Then shortly afterwards demonstrate that their knowledge of the fight does not extend beyond a dated youtube video after wiping the raid several times. Bonus if they don't even know how to play their own job.

[Raminax]

Well, why not try at some terrible humor too, then? D:

Reading? That's for elitist spreadsheet nerds!
This guy is the guy that doesn't Flash and purely spams Rage of Halone. At first, you'd think he merely misread the fine print on the tooltips, but he will insist that he's definitely doing more DPS and healing than the party combined, despite the fact that he's constantly losing aggro, even on the target of his Rage of Halone affections. Almost always a Paladin, weirdly enough.

Roulette! Spin, O' precious wheel!
This one decided that at some point in life, standing still is boring. He will run circles around the boss, and the boss will eventually tank buster cleave half the group, more than likely killing all the healers in one fell swoop while they're hugging and comforting each other. He's not doing it out of malice, though. He's just that bored. Bane of all DPS who rely on positional requirements.

The rock.
Imperishable, indomitable, invincible and all that. Your FC will likely mention that said person once lost aggro at some point, or forgot popping a cooldown and wiped the raid spectularly, but details are hazy, so you begin doubting the stories. Will maintain aggro on the boss for the whole fight, despite disconnecting at 30 % left.