A popular McDreamy flavour. This is a tea drink that uses all three of the neopolitan ice-cream flavours instead of milk. These are strawberry, vanilla and chocolate.
Sometimes referred to as 'a McDreamy with the lot.'
The name is derived from a blend of 'rainbow boss' (a popular coffee drink in Japan) and Maurice Moss (a character from the UK comedy 'the IT crowd').
"I'm feeling adventurous, I think I will have all three of the neopolitan flavours in my McDreamy today."
"So you'll have the rainbow-moss?"
"Yes, that's the one!"