NA Localization:
A guardian beast (or perhaps an attendant) in service of the lovesick queen of a snow-covered land, whom he met on a journey long ago. He resembles a certain Servant, and his temperament is equally fierce, but his actions and manner of speech are somewhat more level-headed. When he takes it upon himself to admonish the queen, he hurls things like codfish with cheese or cheese kamaboko at her... Anything with cheese, really.
There is currently a similar plushie in Chaldea, and it seems to be guarding Master by night, though it's not clear whether it is the same person(?) they met that one fateful day.
Fan Translation:
The guardian beast (Companion) of a Queen full of love, who rules over a country of fluttering snowflakes, whom we have met in a previous journey.
He resembles a certain Servant in appearance, and while his temperament is also similarly violent, aspects of his actions and speech show him to be somewhat intelligent.
Furthermore, he has the tendency to throw cheese products such as cheese sticks or cheese fish cakes when admonishing the Queen.
Currently, a doll that looks the same as him is at Chaldea, and seems to be guarding Master every night, however, whether it was the real person (?) that we met at the time or not is unclear.