Chapter books for a 4 year old boy.

[mootime]

DS (nearly 4) is a real book worm and has just finished his first chapter book courtesy of a MN giveaway, Johnny Duddles' Ghostly Galleon.
Can anyone recommend some other chapter books for this age group?
They don't have to be traditional 'boyish' stories.

This has been well used in our family:
www.amazon.co.uk/Illustrated-Stories-Boys-Various/dp/0746074611/ref=sr_1_3?ie=UTF8&qid=1400968338&sr=8-3&keywords=usborne+book+for+boys

Read it to DS, read it to DD, DS read it, DD started reading it.