Whatever the rules are for choosing 5-character names for IFR waypoints, there is still plenty of room left for poetic licence. There's a GAMBL waypoint not too far from the town of Casino and a WOOLY JUMPA somewhere over the Pacific. And SEXXI NIPPL have been reported in the Philippines.
In the case of a string of waypoints off the coast of Western Australia, inspiration was drawn from a well-known poem by none other than Banjo Paterson, Australia's best-known bush poet:
WONSA JOLLY SWAGY CAMBS BUIYA BYLLA BONGS UNDER ACOOL EBARR TREES
Sing it out loud with me and you'll get the first two verses of Waltzing Matilda, Australia's unofficial national anthem:
Once a jolly swagman camped by a billabong,
Under the shade of a Coolibah tree
Pretty cool, isn't it? There's lots of waypoint trivia out there. Plastic Pilot once proposed to learn French using French IFR waypoints. Pprune.org has some more. The ultimate reference though, at least for trivia related to the UK airspace, is Nick Locke's reportingpoints.info.