1.) Something (a person, animal, object, or anything) that is abnormally larger or bigger in size compared to the things around it.
2.) Something that is just pretty damn huge.
Origin: Red October is line taken from the Family Guy: Blue Harvest episode when they make the "RED" joke where they make various references of "RED" things such as Big Red (chewing gum) then they make a reference to a submarine by the name of Red October. But as they showed the image of Red October there were multiple spacecraft flying beside it that seemed much more smaller than Red October itself thus making Red October stand out in the crowd as a large object.
Ian: If you look at that huge building next to all of those small buildings it doesn't look right..
Kevin: Thats a Red October. LoL!!