2-group raid instance, often known simply as "The Crab"
The entrance is a clickable rock on the island in The Village of Shin. There are no access requirements.
Initially, the crab is non-agro. Right-click and "disturb the crab" and he will spawn 4 74 ^^^ Heroic mobs and he will become attackable as a 74 ^^^ Epic x2.
He's got a massive Cold/Power Drain AE that hits for around 6000~ unless you have cold resists (7000+). You cannot move out of range of this AE, it hits anyone in the zone, but its strength is affected by how close you are to the named (He hits harder at close ranger, but drains more power if you stay further away).
If the DPS ever gets over 5000, he will spawn 4 adds.
At 10% he Memblurs (erases hate list) and spawns 4 adds, so have healers try to save some power for the spike damage this can cause.
See Bonesnapper for a full writeup