Guillermo is an Animalian politician and former soldier currently serving under the Animalian Patriotic Front.
He is an anthropomorphic Great Pyrenees and of the four Spanish dogs is the most formal of them all, in his soldier days he wears black trousers, a white shirt and a dark blue naval jacket whilst in his government time he keeps his trousers but instead wears a dark blue sweatshirt.
Alberto chooses Guillermo to drive the submarine and with good reason because he is someone you can trust to drive a submarine and someone with naval experience and experience in the military and organized crime hence why Alberto is selected to aid the N.P.P in Operation Hood but he is not someone who likes to use light signals believing they do more harm then good because there is the risks *he says* of not being able to see the light, the position being given away or not being seen. And he also says it is worse in a car if someone does not know how to work the lights of the car, like the other Spanish dogs he greatly objects to having the submarine relatively defenceless as it does not use torpedoes or radio to maintain secrecy.
Sometimes he is described as a member of the army but has a much better temper than most generals in the Fox Junta one of them being the Czech general Klement and another general Ludvik primarily to their soldiers, now it could be argued that Guillermo has the most difficult job in Operation Hood having to keep up with the naval escort and having to keep at a certain speed to blend in with other enemy ships yet is still a competent driver. There are also two things that he enjoys and it is the kidnapping of the vixens in Operation Hood and his time in the army. He remains loyal to his allies to the end.