Bertolt Hoover (ベルトルト・フーバー)was an Eldian and one of Marley's Warriors. He possessed the ability to transform into a Titan known as the Colossus Titan. In the year 845, he, Reiner Braun, and Annie Leonhart breached Wall Maria in an attempt to lure out and acquire the Founding Titan for Marley. After that, he joined the military and graduated the 104th Training Corps, ranked 3rd, and later joined the Survey Corps, until his identity as the Colossus Titan was revealed. He was described by others to be a weak-willed and quiet person.