Upsy Downsy was a brand developed by Mattel. It concerns two races of psychedelic creatures, one that lives upside-down (The Downsys), the other rightside-up (The Upsys). These beings and their fantasy world were featured in a (short-lived) line of story books and colorful toys for young kids in 1969.
The toys were plastic characters with fabric clothing and synthetic yarn hair, all in fantastic, garishly bright colors. Each came with a fold-out cardboard Playland mat, the so-called "Magic Bridge Clip", to link one mat to another, accessories, a mode of transportation, and a name that summed up their character in a few nonsensical words.
All of the individual Playland mats were designed to be placed together using the Bridge Clips to make the "Happidiculous World" of The Upsys and Downsys. The Upsy figures were approximately 2-1/2" tall, basically humanoid in shape, with tiny bodies and huge oversized heads topped with a large bright yarn pompom for hair. The Downsys, on the other hand, were more cartoonish beings, about 4" in height with wild, goofy faces in the middle of a large, rounded body. Downsys' hands are positioned on the tops of their heads, to allow them to stand upside-down.
What's it worth? Take a look at this Upsy Downsy price guide: sold listings for a value indication.