Blade and soul gold later killed Bloodshade Harbor Venomous Thrasher
This is the first boss of Bloodshade Harbor. You can stand in the middle without aggro'ing it.
When you're ready you can start dps'ing him. His attacks during the first phase are pretty lax and easy to dodge. They include a 360 degrees spin attack and some swipe attacks. He will cycle through these attacks 4 times and then jump onto the ceiling and enter phase 2.