Creature type (Dungeons & Dragons) animals despite their real-world bases being more closely related to vermin type creatures. Creatures deemed inconsequential by DMs or designers are not given any creature type at all, instead being treated as "set dressing" unless a specific game effect targets such non-creatures. Examples include actual-sized spiders, sparrows, fleas, worms, shellfish, and mice. "Swarm" type creatures are occasionally written to represent such otherwise nonthreatening creatures if they were to group together by some force of magic within the game world. Under the rules of D&D, animal type creatures do not have an Intelligence score higher than 2. When a designer makes
Blood type namely group A, group B, and group C. He defined that group A blood agglutinates with group B, but never with its own type. Similarly, group B blood agglutinates with group A. Group C blood is different in that it agglutinates with both A and B. This was the discovery of blood groups for which Landsteiner was awarded the Nobel Prize in Physiology or Medicine in 1930. (C was later renamed to O after the German "Ohne", meaning without, or zero, or null.) The group AB was discovered a year later by Landsteiner's students Adriano Sturli, and Alfred von Decastello.