Nethermen are highly susceptible to attack from behind, as they infrequently turn around, and when they do, turn around at less than half the normal speed. It is possible to avoid one simply by running past them on the side they are not facing, as they will not be able to get a lock and teleport to you.
Nethermen are different to Endermen in one other respect- as they are found entirely in the Nether, their psyche is almost controlled by lava. They are immune to lava, and can swim through it at the speed that a player normally runs. They move lava blocks instead of other blocks, and so can teleport behind the player and place the block onto the player, effectively killing him. They are also immune to lava, and so will not perish if they fall into it. Theoretically, they could walk around a lava lake indefinitely. They attract ghasts, and sometimes hundreds can converge into their general area. Note that they do not spawn ghasts, merely attract them. They also set fire to blocks in between their teleport locations, This can be used to trap creepers, or other mobs, but can also be the players downfall.
Very rarely, a nether enderman will pick up a block of netherrack, and place it somewhere else, but this rarely happens. In an even rarer instance, The enderman will walk through a portal carrying a block of lava or netherack.
In Destruction of Minecraftia, the Nethermen are the evil henchmen of The Voice in the Darkness and The Eye of Ender, a powerful Enderman overlord. They have conquered the Nether and are now turning their attention to the Overworld. They are leading the Dark Army to conquer everything that stands in their way, including the group of Cody, Alexander, Rowan and Bleek. And in 72 hours, they will sacrifice Steve and Testificate to the Voice and the Endermen shall conquer all!