Nooks are squat, and have deep sunken eyes.
Crannies have a weird head and an angry look. This characteristic was especially repellent to their discoverers and may have helped convince them that it would not only be fun to violate the Prime Directive, it might even be doing these creatures a favor. Senses Nooks and Crannies' primary sense organs are their eyes. Range of sight varies from individual to individual. Improved sight can be cultivated into Nooks or Crannies.