Brood-of-Nine Mesh
The clutch that should have been nine spawn failed to partition on the third day. What came out was one chimeric body with nine mostly distinct nervous systems. Nine voices, one mouth, a standing argument. The Collective considered ending them at decantation, and then decided they were rare enough to keep.
The hive does not enjoy curiosities. The larger chorus could not fold nine parts into itself. After twelve years the high broodmother asked them, politely, to leave. The Quiet Stitch is quiet only by comparison with the argument inside it. In a fight they dispute firing solutions, retreat, and lunch, and a vote they have refined for forty years turns the dispute into an action. Nine of them have to agree before they do something stupid. That raises the bar.
Source: codex:captain_mesh_lord