Mr. Silly is a popular smiley on the Nintendo Pipeline forums. His popularity boomed after users thought it'd be funny to use him in their posts. You see, his eyes look funny! This humor lasts very long, since we are extremely boring individuals.
The history of Mr. Silly is actually pretty short. We try to think up some hilarious backstories to an emoticon, but that just makes it even more tiring of a joke. Basically, someone made a silly face and we think it's hilarious.
While the smiley itself stopped being funny 4 days later, we still like to try to invigorate some life into it so we don't come to the cold realizsation that our friendship is entirely based of hollow in jokes.