Hive Fleet Dagon

Hive Fleet Dagon was the first major Tyranid incursion into the Jericho Reach region of the Ultima Segmentum. A splinter fleet of the extinguished Hive Fleet Behemoth, the Shadow in the Warp cast by the Tyranid Hive Mind within this volatile region of space first heralded the arrival of this new and terrible hive fleet in 812.M41.
The appearance of this Hive Fleet is distinctly noted as the same as Hive Fleet Behemoth, with its bioforms protected by a deep blue carapace over crimson flesh. They do not bleed, but produce a sickly purple ichor when wounded. It is unknown what purpose this ichor serves in the life functions of Tyranid bioforms.
The Tyranid Hive Fleet that is assaulting the Jericho Reach is officially designated by the Imperium as Hive Fleet Dagon and has been identified as the greatest extant threat to the Achilus Crusade underway in the region, and indeed to the lives of every living being in the Jericho Reach. The Space Marines of the Deathwatch remain fully engaged in facing this threat.

Pict-Capture of a Carnifex and Termagaunts breaking through Ultramarine lines during the battle of Maccrage. 745.M41.