Downward Doghouse (partially found Nick Jr. animated series; 2000s)
Downward Doghouse was an animated series on Nick Jr. and a predecessor to Ni Hao, Kai-Lan. It was a part of the interstitial series Nick Jr. Presents: My World. Most of the characters remained the same between series minus some design changes, with the biggest change being that Hoho originally only talked in gibberish, although Rintoo and Lulu were not present at all (an earlier version of Lulu appears in "Dragon Dance" though). Three episodes of the short series are known to exist ("Follow That Slipper", "Where's Hoho?", and "Dragon Dance"). Of these three, "Dragon Dance" has been found and can be viewed below.
Promotional screenshots using the Downward Doghouse designs are available on the Internet. Some storyboards for an episode featuring Rintoo, and using the final designs from Ni Hao, Kai-Lan, but still using the "Downward Doghouse" title have also surfaced.
DaJoshy has found a link to the My World section of the Nick Jr. website, via the Web Archive. None of the episodes work because while the page source does contain file names, no actual video files exist in the page source. Recent findings include an e-card maker and even a full website.
A British dub was also available on the British Nick Jr channel. The UK dub of the "Dragon Dance" episode has surfaced, but the other two remain lost.