Dagon is the alias name for OGRE 1.2.
Dagon is one of the Great Old Ones in the Cthulhu Mythos. The traditional fishy Dagon seems to have inspired H. P. Lovecraft in creating his story "Shadow Over Innsmouth", first published in 1936. This story is one of Lovecraft's best known ones as it introduced the Deep Ones, a race of water-breathing humanoids, servants to Dagon and Cthulhu. Though they strongly resemble fish and frogs , they can cross-breed with mainstream humanity and produce hybrids. This story also introduced their undersea city of Y'ha-nthlei and the port town of Innsmouth, Massachusetts, USA, mainly populated by these hybrids. The Deep Ones and their hybridic descendants are recurring figures in the stories of August Derleth and other of Lovecraft's "Successors". Innsmouth has often been the setting of this stories.
From H. P. Lovecraft's short story "Dagon":<blockquote>Vast, Polyphemus-like, and loathsome, it darted like a stupendous monster of nightmares to the monolith, about which it flung its gigantic scaly arms, the while it bowed its hideous head and gave vent to certain measured sounds.... Once I sought out a celebrated ethnologist, and amused him with peculiar questions regarding the ancient Philistine legend of Dagon, the Fish-God; but soon perceiving that he was hopelessly conventional, I did not press my inquiries.</blockquote>
There is also a Dagon movie from 2001, inspired by the "Shadow Over Innsmouth" story by H. P. Lovecraft, information can be found here.