Droggrel the Golem Master is the Floor 3 boss that you will be expected to fight to move on to Floor 4.
It is larger than the normal golems present in the Floor 3 tower, and is not missing its right arm unlike the rest of the golems. He also may push you back 100 studs, but very rarely. If you are taking on the boss by yourself, then stay at the teleport gate to regen. This boss does a fairly small amount of damage, making its tremendous health the issue. Most, if not all of your health may be taken away if you attack without taking breaks.
It is recommended you tackle this boss with Samurai platemail, anything with better stats will work as well.
You do not need to use a strategy, but a common one is to hit it from the Teleport gate, and regen on it, since he cannot hit you if you move far enough in. With a team, this may not be necessary.
When this boss was first released, there was a large amount of player killing due to the fact that some of the floors had broken, and the ones which were not broken still had large lag issues, making player killing common to get rid of lag and people to proceed to Floor 4.