Venusian Slug

These creatures aren't particularly dangerous, but they do leave sticky slime trails wherever they go. This lowers base hygiene levels, grossing out your operatives and damaging your Tourism Rating. Slugs also reproduce quickly, spawning baby slugs almost faster than you can kill them. Automatic lasers can deal with a few slugs, but larger numbers may require manual lasers. Better yet, prevent slugs from ever reaching your base by placing barriers of high-powered force field posts where they enter the map.