Special infested nydus worms have 1500 hit points on normal difficulty, and disgorge aberrations and regular zerg breeds. It has a boss bar when it appears. They are especially dangerous since the regular zerg do not die when the sun comes up. It yields 10 biomass points when killed. When the sun comes up it disappears.
On "Night 2 Die" mode, the nydus worm gains hit points with each appearance.