[@Athoriel], The Rat King is twice the size of the normal rats, which is to say just a little taller than a man. The link of four bodies allows an all-around view of surroundings, and the Rat King hovers. The bodies aren't individually much stronger than a man, but the fact that two to three pairs of arms can work together makes the Rat King more difficult to fight.

[List]
[*] Greater Reach than its brethren.
[*] Multiple heads make it difficult to surprise
[*] Multiple arms make it hard to pin
[*] Telekinetic floating. No legs.
[/list]