Is he speaking in a certain dialect of the UK?
Native speaker’s answer
Rebecca
Grandpa Pig has a particular speaking style. It is called received pronunciation, and this is the standard form of British English based on educated speech in southern England. It is the standard for British English so it's sometimes (mistakenly) nicknamed the "Queen's English" or "BBC English." It is an accent and not a dialect. It is widely recognizable but not widely used by British people, as accents and dialects differ throughout.