Grashal
this unusual creature was developed by the Yuuzhan Vong as a bio-engineered building or command center, created like their other structures by the secretions of the gricha larva. When fully constructed, the grashal resembled a huge mollusk shell, accessible via a staircase which led to a nexus of tunnels and inner chambers. They could be grown in a number of configurations, standing up to three meters in height and up to sixteen meters in length.