In literature or fiction, a naive hero is a protagonist, usually the narrator, who misinterprets events throughout the work for ironic and sometimes humorous purposes. Through characteristics like innocence, ignorance, and stupidity, the naive hero misses the structure of the plot while the audience clear knows what is going on. Likewise, the hero's opinions and perceptions become faulty and untrustworthy.

There are many famous examples of naive heroes:

As an interesting side note, I realized as I wrote this that many naive heroes are perceived as likable. Through their goofy flaws and ignorance, they present such a backwards narration that people end up sympathizing for them, and ultimately liking them.

Source: Murfin, Ross. The Bedford Glossary of Critical and Literary Terms. Boston, MA: Beford, 1998.