“dwarves” and “elves” are consistent with things like “wolves” instead of “wolfs”, “lives” instead of “lifes”.

Fun fact: this never got applied to dwarf stars, which are still “dwarfs”.

“Dwarfs” is just short for “Dwarf S(tars)”. The plural is on star, not dwarf, and hidden in the shortened version.

(Source: my ass, pleasedon’tquotemeonthis)