E-fapper
Someone who talks so much about everything they know that it feels like they're trying to make everyone else feel dumb. They never shut up and always have to be right.
'You don't even know what a quadratic equation is, you're like a baby in math class'
'I had 1000 followers, you had 2, that's not even a real number'
'I can beat you at chess blindfolded, you're like a turtle in a race'