Skeleton Knights only spawn in Graveyards, Skeleton Piles and when summoned by Necromancers. (In the last case, they have no bounty). They're the stronger variant of the Skeletons. They are spawned in Graveyards when a humanoid enemy with 300 or more maximum health is killed (like Dark Slayers, or Demon Spawns on hard difficulty).
In Kingdom Rush: Frontiers, Skeleton Knights become a friendly unit, raised by Necromancer Towers from big humanoid enemies (i.e. Saurian Myrmidons, Gorillons, Saurian Brutes,...). However, they are much weaker in the sequel, and only have 80HP and 2-10 damage.
Skeleton Knights are the reanimated bones of once great warriors.
Skeleton Knights are more than 3 times stronger than their lesser undead comrades, the Skeletons, with double the damage output, rivaling that of Trolls. Thus, they are deadly to low-level soldiers, and still pose a great threat even to the mighty Paladins. Swarming out from beneath their graves, these warriors can clear out any unorganized, unprepared defense.
- Build at least one tower to keep an eye on Graveyards - they produce lots of skeletons. Good choices are Big Bertha and Teslas, these towers are capable of dealing area damage and thus can destroy groups of Skeletons and Skeleton Knights at once.
- Focus on Necromancers rather than their skeletons. If you just kill the skeletons, more will soon appear. The Rangers Hideout with Poison Arrows is best for this: since skeletons are immune to poison, it will prioritize the Necromancers over them.
- As usual, magic towers are best against armored enemies. While possessing a decent amount of health, Skeleton Knights move slowly, thus is extra vulnerable to the Mages' bolts.