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. Image appeared in "Conradi Gesneri medici Tigurini Historiae animalium liber IV: qui est De piscium & aquatilium animantium natura : cum iconibus singulorum ad viuum expressis fer癡 omnibus DCCXII.", 1604.