Not only is animated adventure Donkey Xote's tagline "From the producers who saw Shrek" distressingly honest, but it's also the movie's only decent gag. The original Shrek was based on the 1990 children's book of the same name by William Steig. The 2001 movie adaptation would greatly expand on the original story which followed the bad-tempered ogre - voiced by Mike Myers (Austin Powers) - as he reluctantly undertakes a quest to rescue Princess Fiona (Cameron Diaz).
Shrek was an instant success upon release for its witty subversion of both movie and fairytale tropes. While it may have dated in certain pop-culture references - such as The Matrix's bullet-time sequence or Smash Mouth's song "All Star" - the movie still holds up. Its success soon led to Shrek 2 which grossed even more than its predecessor, and the franchise became a juggernaut. In addition to two further sequels, it spawned video games, short films, toys and even spinoffs like Puss In Boots, focusing on Antonio Banderas' scene-stealing moggie.
Given the success of the Shrek franchise its only logical other production companies would want to emulate its formula. Donkey Xote from 2007 took that to the next level, with the Spanish/Italian production more or less directly lifting the design of Donkey (Eddie Murphy, 48 Hours) and generally striving to look as much like Shrek as humanly possible.
Donkey Xote is loosely based on the classic novel Don Quixote, with the story involving the rivalry between Quixote and his sidekick Sancho Panza as they compete for the affections of the same woman. The movie is told from the perspective of donkey Rucio, who wants to be Quixote's horse. From the animation through to the humor, Donkey Xote never misses a chance to envoke Shrek. The movie's poster even reads "From the producer's who saw Shrek," attempting to pass it off as mere homage.
Honestly, Donkey Xote has decent animation for a movie that lacked the budget of Shrek and its not terrible, but it's still a shameless knock-off of a much better movie. It's so tied to Shrek that its tagline - which blatantly acknowledges its lack of originality - is the only really solid joke it has. The movie also received video game tie-ins for the PlayStation 2, PSP and Nintendo DS. Donkey Xote is unlikely to receive a sequel at this point and while Shrek 5 is rumored to be in development every once in a while, it seems no closer to moving ahead.