So today and yesterday I've been doing this, practising some photoshop whilst I'm at it. I've drawn the characters and painted them (mostly - see above) on paper And then have added the rest in photoshop.
I quite like it. I'm slowly moving off the 'creature' idea and more towards a Giant Baby...or, well, a Baby Giant? A Newborn Giant, and going with a bit of a BFG feel.
I'm going to stick a lot with drawing and painting by hand as it's so much quicker for me, and easier. I'm also thinking of calling the project "Big" because I had this idea that the boy was mentally disabled and hadn't learnt to talk properly yet (I'm thinking he's about 3-4 years old but mentally is about 2 years behind) and he meets this Giant and out of that his first word is "Big" and so he calls the Giant, 'Big'.
I'm still keeping with the mum not wanting to grow up idea. Although I haven't started on her character yet. I'm also looking more into the setting and thought of adding a Crazy 60's Architect who built the "New Town" (on my reading of Milton Keynes it turns out there were a lot of wonderfully crazy ideas on building towns about this time). However that he built it using Giant-slave labour to create his wacky ideas and managed to work them all to death so this Giant is now the only one left and the little boy has to teach him the ways of the world.
I then thought somehow the mother and the architect could have a love interest. I'm not sure how it'd work. I'm still working with the 'something for everybody' In that the mother brings adult themes to the story, and the boy and the giant appeal to the children and the architect brings a bit of comic relief, although I might make him sinister. Anyways. All that to enjoy over the next week.