Scuds are the fifth species of sapient alien in Runaway to the Stars, and first contact is made with them during the the story. They’re usually called scuds (a common name for earth’s amphipods) but have several other English nicknames, mostly things like parrot crabs and mitten shrimp. They are amphibious animals who can breathe air as long as their gills stay moist, but are most comfortable submerged and primarily live in saltwater intertidal zones. Depending on region, their industry is at an equivalent level to something like 1980s-2010s human civilization, and is divided over both land and sea depending on need. Most of the transport infrastructure scuds have built onto land are railways with cars full of baffled seawater.