*"Merm" is an abbreviation for "Mermen" or "Merman".
*Merms are almost certainly based on ''The Deep Ones'', a race of fish people from the horror fiction of American author H. P. Lovecraft who live in Innsmouth, a run-down town similar to the Merm towns in Don't Starve.
*Maxwell, when examining the merms, mentions that "they were here when I got here". However, In the ending speech he gives Wilson at the Nightmare Throne, Maxwell states that all that was present when he arrived was "dust, the void, and '''them'''". Them is inferred to mean the shadow creatures controlling Maxwell, who are most likely responsible for the creation of the merms. In Lovecraft's lore, the Deep Ones serve the Elder Gods, incredibly powerful eldrich entities such as Dagon, Hydra, and Cthulu. This may imply that the shadows controlling the world of Don't Starve are inspired by Lovecraft's Elder Gods.
*Kevin answered the question "Why Merms drop Fish?" in the ShannonZKiller's Pre-release twitch. The answer was "They are made of fish."
*[[Pig Head]]s, as of ''[[Version History#The End is Nigh|The End is Nigh]]'' update, spawn in Merm villages, and along [[Road]]s passing through [[Marshes]]. This suggests some kind of hostility between the two tribes of animals. Similarly, [[Merm Head]]s spawn inside some Pig villages. This probably to show them as trophy, or to intimidate.
*Merms are instantly hostile (unless fighting something else) when spawned via the [[Console]] because they have no house to placate them.
*Merms seem to have normal walking speed, but during dusk they are faster. They are also faster than Pigs.
*Despite Merms being able to run faster, they can be easily outrun as they stop when they hit allowing the player to run while they catch up.