Also, I really think only the big 'red' fella should be called a titan. :p The other small ones' designs were, in my opinion, not so impressive and they were very small compared to that huge guy. Small ones should be called giants or something. lol
also why didn't the big guy just bring down the whole damn wall? He was easily capable of doing so but the only thing he did choose to do was open up a hole. That's sorta weird. :p
No, all giants are known as titans. :3 And titans are classified with their heights.
There are 3-5 Meter titans, 7 Meter Titans, 15 Meter Titans, and etc... :3
And that huge guy is the Colossal Titan (So technically it is a titan :p) and it can't destroy the wall at all. It can only destroy the gate in the wall in order for other titans to get in the town.