Nickelodeon's preschool-aimed, educational, interactive, bilingual animated TV show "Dora the Explorer" had a pilot episode. It is unknown when this pilot was completed, but as of 2018, Funline Animation, the company that helped produced the pilot, uploaded a short clip of it on their website. There are two unaired pilots. A clip of the first pilot can be viewed here. In this pilot, we can see that Dora and her friends went to the beach. The ending of the second has since resurfaced which can be viewed here.
"Test Pilot"[]
This pilot can be found online, however, the audio (if any exists) is unavailable. Dora has the final-cut design, however, Boots still isn't the same as the final cut.
A clip of the test pilot: https://www.youtube.com/watch?v=gMX0cUGVxbQ