The nickname of the mysterious creature in Alaska's Lake Iliamna that has confounded local residents and explorers since the 1970s. Dubbed the Alaska lake monster, Illie even led to the Anchorage Daily News to offer in 1979 $100,000 to anyone who could provide evidence of its existence. The prize was never claimed.

Recent studies have suggested that Illie may be just a Pacific sleeper shark which has managed to survive in the warm fresh waters of Lake Iliaman. Also known as Greenland sharks, the sleeper sharks are commonly seen in the waters around Alaska and have been known to grow up to 14 feet in length. However, sleeper sharks are not known to survive for extended periods of time in fresh water.

The sleeper sharks traditionally live in the icy cold depths of the Arctic but have recently been seen in warmer waters, including the St. Lawrence River near Quebec's Baie-Comeau, due to the effects of global climate change.