Humbley will be joined in the cast by Spamalot's Jon Robyns and Kit Orton, as well as Gerard Carey and Matthew Hendrickson.
It runs at the Arts from 2 December 2013 to 5 January 2014 (previews from 27 November).
Characters played by the multi-tasking cast include Fagin, Scrooge, Miss Havisham, David Copperfield, Oliver Twist and Mr Micawber.
Full casting has been announced for the Royal Shakespeare Company's world premiere of Ella Hickson's Wendy and Peter Pan, billed as a "fresh new adaptation of the much loved children's classic by JM Barrie".
Directed by Jonathan Munby, the festive family show will open for previews in the Royal Shakespeare Theatre on 10 December 2013, ahead of press night on 18 December.
They will be joined by Michelle Asante (Tiger Lily), Simon Carroll-Jones (Shadow), Richard Clews (Knock Bone Jones), Matt Costain (Peter's Shadow), Gregory Gudgeon (Smee), Susan Hingley (Shadow), Emily Holt (Shadow), Jack Horner (Shadow), Arthur Kyeyune (Doc Giles/Crocodile/Shadow), Will Merrick (Slightly), Jack Monaghan (Nibs), Dodger Phillips (Murt the Bat), Guy Rhys (Doc Swain), Dafyyd Llyr Thomas (Curly), Jamie Wilkes (Martin) and Josh Williams (Tootles).