First boss of Zul'Gurub and pretty easy

Jeklik's Abilities

Summoning Bats: Jeklik will use this for the phase 1 part of the fight summoning a swarm of bats to aid her. These can be dealt with by AoE.

Heal: Once she goes into troll form she will attempt to heal herself. This heal can restore up to 50% HP and thus should be interrupted at all costs. Use Shield Bash/Kick/Pummel/Silence

Bomber Bats: Once she is in her troll form she will occasionally summon a bat rider that will fly above you and drop fire bombs. These bombs deal 800-1100 damage and deal around a 250 damage DoT. Get out of the fire as fast as possible.

The Fight:

Have your Main-Tank move in and grab Jeklik and after the first couple sunders begin to DPS like crazy. Jeklik will occasionally charge a random party member so have everyone be ready to run to the MT if they are charged.

If you wish to you can use your mana draining spells on her to keep her from using her troll form abilities. If doing this dedicate 2 warlocks using mana drain with help from the hunters using viper sting to drain her mana.

Everytime a batch of bats spawns pull them off the MT as this will kill him. Have your mages co-ordinate AoE to take them down as fast as possible.

Once Jeklik hits 50% HP she will go into Troll form again, make sure that she never gets a heal off using everything possible from kick to pummel and Earthshock.

During this Phase have everyone scatter around the area as to prevent mass damage to the group from the fire bombs. Make sure the MT pulls out of the flame as well as all the DPS. The Bombs remain in a fiery circle after being dropped for a little bit so stay out of them.

Just have DPS go all out and burn her down.