Dagger Aliens

These aliens are seen for the first and only time in Ben 10 Alien Force: Vilgax attacks.

are seen in the levels of Bellwood, Bellwood Revisited Null and Void.

Fat aliens are blue, with muscular arms and legs, black spots, black spines on their heads and yellow eyes, they see armed with 2 knives, because they appear once activated Vilgax projector, presumably are Null Void