This floating enemy first shows up on the later levels of Table Mountain. It's special ability will knock your sword (or your shield) away leaving you naked and free to be pummeled at its leisure. You can pick up the knocked away items though, at a cost of a turn and at the cost of another turn, equip it again. However, it is highly suggested that you do not face Metal Armor within range of water since it can easily knock your best equipment into the water and be unrecoverable. The same thing is true if enemies are behind you; if the knocked off item hits an enemy, it will deal 2 damage to them and disappear. Additionally, having a weapon knocked away is equivalent to throwing it in that direction, and the Pitcher's Armband will take effect accordingly, leaving you to watch your prized equipment sail off into the ether.

On the other hand, eating the meat of this enemy is the easy way to upgrading your equipment. You gain access to it's equipment removal ability but only one item per monster. You can run around the dungeon, knock away all the monsters equipment, kill them after and revert back to Shiren to collect all the loot. You can get Dragonkillers, Dragonwards, Razor Winds and Evasive shields this way.
[AangZhu12: I'd like to note here that technically, the Cell Armor forces you to throw the shield, so don't wear a Pitcher's Armband when around these things. I lost a 99 Stormward because of this