Lobsters were armored crustaceans that dwelt on the seafloor among rocks, crevices, and sandy shelves, favoring cool coastal waters over warmer shallows. Their hard exoskeletons ranged from mottled green-brown to deep blue in life, and grew progressively larger and more cumbersome to shed with each passing year, a process that left the creature soft and vulnerable until the new shell hardened. Adults commonly measured 25–50 cm (10–20 in) from claw to tail, though old individuals that had molted many decades were known to grow to considerably greater size. Most lobsters had a conspicuous feature, a pair of unequal claws, one thick and blunt for crushing shell, the other sharp and slender for tearing flesh.
Lobsters were scavengers and opportunistic hunters, feeding on mollusks, Earthworms, and the occasional dead fish that settled onto the seabed, using long antennae to feel their way through dark or silted water. They were largely nocturnal, sheltering in burrows or under rock ledges by day and emerging at dusk to forage. Though solitary by disposition, lobsters were not above stealing from one another, and disputes over shelter or food were settled with raised claws and, occasionally, lost limbs, which the creature could regrow over successive molts.
Coastal Mortalborn regarded lobsters as a humble food source for much of their history, easily gathered from tide pools and shallows, though their reputation shifted markedly wherever trade routes made them scarce and fashionable.