The top half of a grindylow looks vaguely like that of a goblin, but from the waist down, their bodies split into a tangle of suckered, wriggling tentacles. They dwell mostly in shallow waters both fresh and briny, including lakes, rivers, coastal regions, and near coral reefs. Grindylows generally organize into schools ranging from a few individuals to a few hundred. Smaller schools can sometimes be brought under the leadership of a powerful aquatic creature, though such alliances last only until the school faces a major setback, at which point the surviving grindylows scatter and form smaller schools of their own.