Crypt Fiends are large, mummified creatures who appear to be a genetic cross between humans and spiders. Their lower bodies are supported by six spindly arachnid limbs and their heavily bandaged torsos are human in form. The cunning Crypt Fiends were once the lords of the ancient spider kingdom of Azjol-Nerub that spanned the entirety of Northrend in ancient times. However, the Crypt Fiends' power base was destroyed by the Lich King, Ner'zhul, when he and his undead Scourge took control of the frozen continent. Now the Crypt Fiends command their spider underlings in the name of their master, Ner'zhul. These aberrant creatures are capable of summoning swarms of vile insects and projecting web-like strands to incapacitate and harm their enemies.
Combat support creature. Can learn the Web ability. Attack land units.
Crypt Fiends are great additions to a melee force. You should use Crypt Fiends when facing air units, as they are the main defense against air units besides Gargoyles because of their Web Ability, which allows Crypt Fiends to bring air units down to earth. Crypt Fiends do not have an air attack but their Web ability allows them and other melee units to attack a webbed air unit.
Players sometimes focus entirely on Crypt Fiends in team games. This can be an effective strategy. Be reminded that Vampiric Aura does not work with Crypt Fiends. Proper Crypt Fiend usage involves a lot of running.
Spells & Abilities
If you're building Crypt Fiends be sure to research Web. It's a cheap upgrade and it's good to have it available on the fly rather than having to wait for it if you get in trouble against air units.
Webbed air units cannot move, and count as ground units. This means that units with ground attacks can now attack them, and also that units with no ground attacks cannot. Webbed units only count as ground units for attack targeting purposes. You cannot, for example, Possess or Impale a webbed air unit. Units with a good air attack but a poor ground attack, such as Gargoyles, do not mix well with Web.