Kumonga (also known as Spiga) was an enormous spider presumably native to Sollgel Island, discovered by Dr. Tadashi Matsumiya during his stay on the island after World War II. Kumonga would hibernate for long periods of time by burying itself underground in a valley on the island, waking up every seven years or so to feed. Kumonga was woken from its seven-year slumber by Minilla (Minya), who at the time was trying to evade a Kamacuras (Gimantis). The monstrous arachnid then made life pretty miserable for Professor Kusumi's team, as well as Dr. Matsumiya's daughter Saeko. Ultimately, Kumonga made the mistake of attacking Minilla, and was destroyed by him and Godzilla.
Unlike the Kamacurases, who were man-sized before growing to a height of 150 feet as a result of a radioactive storm, it is not known precisely where Kumonga comes from. However, Dr. Matsumiya's notes have the spider already a giant monster by the time he and Saeko arrived on the island, so that much is known. Kumonga was capable of spinning a strong web that could only be broken by intense heat, and also had a poisonous stinger with which it killed its prey.
In the English dub of Son of Godzilla Kumonga's name was changed to Spiga.