Colossal Titan is one of the largest Titans. It attacked Shiganshina district and allowed the Titans to come in.
The Colossal Titan is 60 meters tall, a body resembling that of humans with their bare muscles showing and an ability of releasing smoke due to his body high temperature preventing almost anyone to come close.
Later on, it is revealed that Berthold Huber is the Colossal Titan.
Due to his large size, he is slow footed.