"Crush the intruders!"; "You're so little!"; "Human flesh - delicious!".
Behavior:
Behemoths attack their enemies and chase them with their great speed. A behemoth will never retreat (they fight until death).
Field Notes:
When it's hasted it's able to outrun a level 130 player. So always be prepared to use Haste or Strong Haste. It can also be skinned in order to get Behemoth Fangs.
A team of a Knight and a Druid at level 70 can hunt these with much profit and experience using the Ice Strike and Heal Friend spell. A Paladin, lower level than 80 should have a blocker or hunt solo from level 85+ with 90+ distance. Hunting them is easy and usually there will be profit in Loot.
The Arena Quarter is a perfect place to try out your first behemoth. Casting a DoT spell such as Curse, followed by going down again is a good idea since the behemoth does not heal. Frequently recasting such a spell when the damage is down to 10 per round can kill the behemoth in about 5-10 minutes without putting yourself in too much danger.