Book series recommendations please - also info on Beast Quest and Mr Gum

[DancingInTheRain86]

Hiya, I am looking for some book series for my 9 year old son for Christmas. I don't think he'd like massive books but he is a good reader. He already has all the Flat Stanley books, Roald Dahl and Diary of a Wimpy Kid, and a just bought the Chronicles of Narnia books.
Could anyone recommend some good book series for a 9 year old boy please?
Do you think he might enjoy Beast Quest or would it be too ''young'' for him? And what sort of age are the Mr Gum books good for please? I don't know much about that one.
Thanks in advance :)

Oh also ''Stitch Head'' if you guys have heard of that, thanks, lol :)

The Alex Rider series by Anthony Horowitz is basically a young James Bond. If this looks a little too much for your son, try Horrowitz's Diamond Brothers series.
Who Let The Gods Out by Maz Evans is a hilarious book based on a school boy's adventures in Ancient Greece and will appeal to reluctant readers.
The Incredible Adventures of Professor Branestawm
Emil and the Detectives
Scribbleboy
Animalcolm
Anything by David Williams
A Series of Unfortunate Events

How to train your dragon
Dark Lord series is humorous
Football Academy series from Tom Palmer (he also has a rugby series)

The Tom Gates series by Liz Pichon ( my 9 year old DS loves these)
Also a series called Middle School which is American but seems quite similar to Tom Gates in style

My 10 year old has enjoyed the Stitchhead books, Tom Gates, Barry Loser and Skullduggery Pleasant.

At 9 I'd say he's probably on the verge of being too old for Beast Quest.

Oh and all of the David Baddiel books - especially The Person Controller and The Parent Agency.

Too old for beast quest (lucky escape!!) Heroes in training might be a better fit.
Dark is rising
Charlie Bone

Beast Quest probably a bit too young for him. How To Train Your Dragon is good, and - surprisingly - so are the Captain Underpants books.

He's too old for beast quest. But love love love Mr Gum - well me and now 10 year old ds. Read from 8 onwards. Highly recommend!

I would say too old for Beast Quest.
Seconded Alex Rider.
A slightly easier book if he finds them too much are the Roman Mysteries. They're similar standard I'd say, but shorter.
My ds is working through Biggles at present, but his all time favourites are the Lone Pine Series by Malcolm Saville. Out of print, so you need to get second hand.
He also enjoyed the Naitabal set
which are great fun. Although prepare for a sudden interest in buying penny stamps and speaking in the Naitabal language.