Ralph is a tall man with a short crop of brown-colored hair and eyes. He is usually seen wearing the Military Police uniform.
Like most Military Police, Ralph looked down upon those from the Scout Regiment. However, in contrast to his companion Sannes, Ralph may not be as devoted to the king and keeping the security of the Walls, as he ended up going along with the Scout Regiment's plans in compensation for his own life, ultimately betraying the secrets of his companions and organization. As a part of the Interior Police, his job was to dispose of people viewed as threats, such as brutally assisting with the murder of Pastor Nick.
After receiving word that Pastor Nick from the Order of the Walls has divulged valuable secrets to the Scout Regiment, Ralph and Sannes, are ordered to find out how much he told. Visiting the man, Ralph savagely beats and tortures Nick. Despite his best efforts however, Nick refuses to talk and eventually dies without saying anything.
Ralph and his companion cover up the torture by claiming that Nick was killed during a burglary gone wrong. When Nick's friend Hange Zoë attempts to investigate, the two refuse to allow her entry, claiming she will interfere with the crime scene.
Ralph and Sannes are later contacted by a merchant who claims to know the location of Levi and his squad. Allowing him to lead them to a remote cabin, the two arrive to find that they have been double crossed, and are taken captive by Levi's squad.
Sometime after his capture, Hange and Levi take Ralph to a stairwell in the cabin and force him to read aloud a script that they have written for him. The script has Ralph openly criticize Sannes for his blind loyalty to the king, and ask the Scouts to kill him as he is a nuisance to his fellow policemen.
Ralph's captors eventually reunite him with Sannes, placing them in a cell together. Glad to finally see his friend again, Ralph tries to check on Sannes's wounds but Sannes begins choking him, accusing Ralph of betraying him. Hange stops Sannes, revealing to Sannes and Ralph that she and Moblit forced Ralph to read a script outside of Sannes's cell to break Sannes, and get him to answer their questions. Sannes is devastated, and Ralph angrily calls Hange a monster.
- Djel Sannes - Ralph's companion and friend, the pair were always seen together and appeared to be close prior to being captured by Hange and Levi. While a hostage, he ends up insulting him, claiming to not care about his injured condition and asking for him to be killed, however that was not Ralph's true feelings, as he was being forced to read from a script at knifepoint.
- He and Wald share the same Japanese voice actor.