Heavens to Murgatroyd
An exclamation of surprise.
'Heavens to Murgatroyd' is American in origin and dates from the mid 20th century. The expression was popularized by the cartoon character Snagglepuss - a regular on the Yogi Bear Show in the 1960s, and is a variant of the earlier 'heavens to Betsy'. Despite etymologists' best efforts there isn't any record of the phrase that predates the cartoon series and it seems quite likely that it was coined by the show's writers.
As with Betsy, we have no idea who Murgatroyd was. The various spellings of the name - as Murgatroid, Mergatroyd or Mergatroid tend to suggest that it wasn't a reference to an actual person but just a fanciful expression made up because it sounded wacky.
No fewer than ten of the characters in Gilbert and Sullivan's comic opera Ruddigore, 1887, are baronets surnamed "Murgatroyd", eight of whom (or is that which?) are ghosts.
Where then did the librettist Sir William Gilbert get the name? It seems that Murgatroyd has a long history as a family name in the English aristocracy. In his genealogy The Murgatroyds of Murgatroyd, Bill Murgatroyd states that, in 1371, a constable was appointed for the district of Warley in Yorkshire. He adopted the name of Johanus de Morgateroyde - literally John of Moor Gate Royde or 'the district leading to the moor'.
Whether the Murgatroyd name took a trip from Yorkshire to Jellystone Park we can't be certain. Unless there's a Betsy Murgatroyd hiding in the archives, that's as close as we are likely to get to a derivation.