In Jewish folklore Tannin is the name of an aquatic demon

Demon

call - 1347 531 7769 for more infoIn Ancient Near Eastern religions as well as in the Abrahamic traditions, including ancient and medieval Christian demonology, a demon is considered an "unclean spirit" which may cause demonic possession, to be addressed with an act of exorcism...

. Sometimes he is compared with Rahab, another sea monster

Sea monster

Sea monsters are sea-dwelling mythical or legendary creatures, often believed to be of immense size.Marine monsters can take many forms, including sea dragons, sea serpents, or multi-armed beasts. They can be slimy or scaly and are often pictured threatening ships or spouting jets of water...

 who is especially associated with the Red Sea

Red Sea

The Red Sea is a seawater inlet of the Indian Ocean, lying between Africa and Asia. The connection to the ocean is in the south through the Bab el Mandeb strait and the Gulf of Aden. In the north, there is the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez...

. Some scholars associated Tannin with Tiamat

Tiamat

In Babylonian mythology, Tiamat is a chaos monster, a primordial goddess of the ocean, mating with Abzû to produce younger gods. It is suggested that there are two parts to the Tiamat mythos, the first in which Tiamat is 'creatrix', through a "Sacred marriage" between salt and fresh water,...

, as it happened with Rahab. It is unclear in Jewish literature the differentiation between Tannin, Rahab, and Leviathan

Leviathan

Leviathan , is a sea monster referred to in the Bible. In Demonology, Leviathan is one of the seven princes of Hell and its gatekeeper . The word has become synonymous with any large sea monster or creature...

, but Tannin and Rahab are more easily confused one with the other. Tannin, as well as Rahab, was a name applied to Egypt

Egypt

Egypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...

 after the exodus of the Israelites from that country.

In modern Hebrew the word tannin (תנין) literally means crocodile

Crocodile

A crocodile is any species belonging to the family Crocodylidae . The term can also be used more loosely to include all extant members of the order Crocodilia: i.e...

.