Phineas and Ferb: Spot the Diff (found animated TV special; 2008)
Logo for the marathon block
Date found: 16 Jun '17
Found by: Bootleg Frog
Phineas and Ferb: Spot the Diff was a two-hour long special that aired on August 8th, 2008 on the Disney Channel early in the run of Phineas and Ferb. In this event, certain episodes were altered slightly. The changes were minor, such as changing a character's hairstyle or changing their colour scheme and other things as a challenge to the viewers to find the total number of such differences in an episode.
Recently, the original creator of this post was contacted by someone from El Salvador, saying that the lost episodes from the "Spot the Diff" marathon are available on a Latin-American website called pyflatino.com. The episodes are only available in Spanish but are in good quality. The episodes included in the Marathon are "The Fast and the Phineas" (English and Spanish), "Toy to the World" (Spanish), "Lawn Gnome Beach Party of Terror" (Spanish), and "It's a Mud, Mud, Mud, Mud World" (Spanish)
All episodes were uploaded to YouTube by user the_driver_2001 and were available in Spanish only. Those have since been taken down for copyright. On June 16, 2017, TheZapster (Bootleg Frog on the Wiki) uploaded all the episodes to Vid.me in English.