A Wobster is a catchable sea creature found in the Shipwrecked DLC. Wobsters spawn from Wobster Dens, each den will house one Wobster. Wobsters are nocturnal, and will only come out at Dusk, will stay out all through the Night, and will retreat back to their dens when the next day begins. Player getting too close will also cause them to be scared and go back to their dens.
They can be caught using Sea Traps or a Trawl Net. They are attracted to Limpets, which can be used to bait the trap to improve chances of catching them. Leaving them caught in a trap will cause them to starve to death in 1.5 game days, dropping one Rot instead. Wobsters that have been dropped on land by the player will not move and die after a short amount of time.
When alive, they can be used in Crock Pot recipes. As inventory items, they can be murdered by right-clicking them to produce a Dead Wobster. The dead version can only be eaten raw or cooked, and cannot be used in Crock Pot recipes.
Being able to only use live Wobsters in the Crock Pot is a reference on how lobsters are cooked in real life - they are put in boiling water alive. This is because lobsters naturally possess harmful bacteria that can quickly spread once the lobster is dead.