Basically, an unreliable narrator is when you write in first person and the subtext implies that the narrator doesn’t know everything about a situation. Which is pretty realistic tbh, there are situations you’ll have a completely biased view about since well…you’re human 
a great example of this being used is in a book called The Remains of The Day.
Can you think of any more examples?
Omg!! Can’t think of non!
The secret history!! Richard Papen. But I love it
Good Old Nick from Great Gatsby
GOOD ONEE!
Megan?
We were gonna originally look at that in class but the teacher chose Remains of The Day instead which I actually quite enjoyed the prologue of I don’t have access to the whole book but the prologue was definitley enough to understand the affect of this style of narration.
Megan? 
Megan FOX!
Okay but
Why is she an unreliable narrator?
She a lier! In every book and movie.
That doesn’t really count, unfortunately xD
She played in jennifer body! And mostly all the transformers
The Call of Cthulhu has an unreliable narrator, too! Lovecraft loves to utilise madness as a way to confuse and obscure in his work
I don’t think smart. 
The interesting thing is that the narrators of Lovecraft’s work often question their own sanity! They know their own thoughts and feelings can’t be trusted when the world around them is going so mad
I think you’ve just got the wrong end of the stick! We’re talking about characters who narrate the story, so we see the story through their point of view.
However, due to bias or madness or guilt or forgetfulness or any other reason, you can’t trust that their version of the story is 100% true
YES LOVECRAFT I WAS GONNA SAY HIM!
I haven’t read Cthulhu but I have read some of his others!
There’s a short story Poe wrote that used an unreliable narrator and managed to convince the public that his case his invented was real. But the narrator wouldn’t tell the other peoples names and such.
Oh and I think Bram Stoker inspired Lovecraft and although not as much this is some unreliability in Dracula. At least you can probably argue that.
I’m glad you found other examples because I was struggling xD
In my mind, all narrators are at least a little bit unreliable because they have their own biases and ways to tell a story, details to miss out, etc! It can be hard to find explicit examples!