Nautilus has one of the longest attack animations of any champion. This can lead to odd and unexpected hits, as the enemy finds themself stunned or damaged, even though they are visually beyond his range. It is sometimes unclear at what point in the animation an attack is considered to have hit.
Nautilus was released without the "Tank" tag, but it was confirmed that the absence of the tag was an error which would be fixed. Nautilus is indeed primarily a tank.
When Nautilus stands idle long enough, he does the famous Captain Morgan pose.