Translation: a portmanteau of slug and whale; slugwhale
Habitat: homes and gardens; as a regular slug
Diet: leaves and plants
Appearance: As its name implies, the namekujira is a very large slug. Its body is described as reddish-brown in color, with a long stripe running down its back. From its head to its neck, it is covered in black spots.
Behavior: Namekujira live in gardens and behave just like ordinary slugs. It is their size that makes them so strange. They crawl across doors and fences, leaving behind enormous, silvery slime trails up to 100 hiro in length—almost 182 meters.
Origin: Namekujira is described in the Kujirazashi shinagawa baori, a comical Edo-period book featuring different types of pun-based whale yōkai. Its name is a play on words, combining the words namekuji (slug) and kujira (whale). In addition to its name, this yōkai’s description contains one more pun. There is a dish made from whale intestines called kujira no hyakuhiro. The name literally means “whale’s 100 hiro,” which comes from the great length of the whale’s intestines. So the gag is that while kujira no hyakuhiro refers to a delicious meal, namekujira no hyakuhiro is just a 182 meter long slime trail.