A founding member of the Guardians of the Galaxy, the original Yondu Udonta first appeared in Marvel Superheroes #18 in 1969. This blue-skinned, large mohawked alien was the last surviving member of the Zatoan tribe in the far-off 31st Century. As a character, he fit into the "noble savage" archetype, a spiritual being who was eager to serve and help his fellow Guardians.
Marvel Studios decided to take this character in quite a different direction. Rather than a faithful servant who was all about teamwork, James Gunn wrote Yondu as a father figure for Star Lord, and a fairly lousy one at that. This rough-and-ready space cowboy version of Yondu was played with grizzled menace by Michael Rooker, star of Henry: Portrait of a Serial Killer. He was such a hit that he was given an even bigger role in the sequel, being promoted from comic relief to the ultimate hero of the story.
The next time we met Yondu in the comics, he was a completely different person from his first appearance. And we do literally mean a completely different person - because the original Yondu lives in the 31st Century, the Guardians of the Galaxy comic could easily introduce a brand new character who lives in the present day. It's just an amazing coincidence that he also happens to be named Yondu Udonta, and that he looks and acts exactly like he does in the movies.