elf vs pixie

elf and pixie both are nouns.

Word	Noun	Adjective	Verb	Adverb
elf	Yes	No	No	No
pixie	Yes	No	No	No

As nouns, elf and pixie are synonyms defined as:

Other synonyms of elf include brownie, gremlin, hob, imp, pixy.

elf (noun)	pixie (noun)
(folklore) fairies that are somewhat mischievous	(folklore) fairies that are somewhat mischievous
	creeping evergreen shrub having narrow overlapping leaves and early white star-shaped flowers; of the pine barrens of New Jersey and the Carolinas