1992:
SODA SIPPIN' PONIES
Without undermining these two ponies, who are, actually, quite pretty with their curly hair and bright colours, I think that Hasbro were really scraping the creative barrel a bit when they released this set. There are two ponies, each in the same pose, and each was sold with a sundae and a long straw. The ponies have a big hole in their mouths to fit the straw into, so they can "Soda Sip."
They were sold with their hair in ringlets, similar to the Rainbow Curl Ponies or Candy Cane Ponies, but in three distinct colours. The curls are often messed up on loose ponies.
These ponies were part of the 10th Anniversary year in the North American release, but they weren't ever sold in the UK.
Probably because the idea is completely nuts xD.