Monodon monoceros is commonly known as the narwhal - a toothed whale species found in arctic waters. This unique creature has long been a source of fascination for researchers and animal lovers alike, but they may not always refer to it as "narwhal". Some of the synonyms for Monodon monoceros that are used include "unicorn of the sea", "sea unicorn", "gray whale", "polar whale", and "corpse whale". These alternative names reflect the creature's rarity and distinctive features, particularly its long, spiraling tusk (actually a protruding tooth) that can grow up to three meters in length in males. Narwhals are fascinating creatures that continue to capture our imagination, no matter what we choose to call them!