So, according to the Monster High wiki, the line has gone under many names in multiple listings including both Sweet Treats and Dessert Ghouls, but the wiki refers to it as Dessert Ghouls because that was the earliest listing title and it makes sense for a contemporary MH line.

Funnily enough, my friend Ki was so used to the line being so expensive (I don't think Mattel made a lot of the dolls for this one) and being called Dessert Ghouls, that she thought the Cleo doll was the hardest to find! None showed up on eBay until we searched "Monster High Sweet Treats" on Google, and later found multiple listings for Cleo's doll in the box at around $30 including shipping.

We found Ari's doll for $23 and $40, both out of box and unfortunately, Catrine's doll was still $45-$55. Apparently she's gone for more, according to one Mercari seller's description. However, Ki managed to snag me one for $35 including shipping! And do you want to know how we found out about this line being called Sweet Treats?

..The sticker on the box in the seller's pictures said so!

Alistair Wonderland Signature - Royals doll from Ever After High by Mattel

Release: May 2015

Assortment number: BBD51

Fakie pinkie cooper review:

Bad news: you get 3 dolls in hotglued clothes and fakie barbie shoes that stain the white vinyl of their feet, there’s flash in the joints and the legs lack the chunkiness of the originals. The facepaint is stained with yellow, has rubs and is fuzzy at the outlines. The nylon hair is of course turrible.

Other than that: The bodies retain the same amount of articulation (jointed arms, hips, 3 click knees) and are much easier to remove than the originals. Their size (17cm) and cuteness make them excellent for anthro hybrids such as large LPS. The eyes are easy to maneuvre and an easy switch for 20mm half round eyes (I only have 24mm at the moment) with false doll or human eyelashes. The eyes they are supplied with can be smooshed into position if you’d rather keep them and their odd inset eyelashes. The heads are slightly larger and flatter faced than the originals. The heads are brown, tan and black bases with white painted necks and lower faces. Ideal bases for rabbit, bear or other anthro doll customs.