Halberds and Glaives are high-damage pole weapons with long range. Units with Halberds or Glaives tend to have excellent damage potential but are vulnerable to missile attack because they have no shields. Halberds get -1 to both Attack and Defence.
Found on some Atlantian units, the Coral Glaives are length 4 weapons with Poison. Together with poison and high damage, is likely that a normal unit will die from an attacker using a Coral Glaive.