He looks very different.

There was a bit of a 'Harry Potter' and 'His Dark Materials' cross over in last night's episode of the BBC drama.

Eagle-eyed viewers spotted that Trollesund citizen Sysselmann looked very familiar, and was only the same actor who played Dudley Dursley in the 'Harry Potter' movies.

Trollesund citizen Sysselmann played by 'Harry Potter' actor Harry Melling.

Sysselmann is played by Harry Melling, who actually also showed up an hour later in BBC's 'The War of the Worlds'.

Harry Melling alongside Rafe Spall in 'The War of the Worlds'.

Episode 4 of 'His Dark Materials' also featured the introduction of Lin-Manuel Miranda as aeronaut Lee Scoresby and armoured bear Iorick Byrnison, (voiced by Joe Tandberg). However, fans were much more interested in Dudley Dursley.