As nouns the difference between murry and murr
is that
murry is moray eel while
murr is (obsolete) a catarrh or
murr can be (onomatopoeia|colloquial|furry fandom) a purr (produced by any animal).
As a verb murr is
(onomatopoeia|colloquial|of a person or animal|furry fandom) to purr.