I've read that children on the autistic spectrum often use 'scripts' as a way of communicating and I've noticed just recently that Nipper is doing this, although in a minor way at present.
His favourites are:
'Rocking rasperries' and 'rocking cucumbers' from 'The Mr Men'. He'll have to be careful with this one as it often sounds likes he's saying something else!
'Oh, custard!' from a very old 'Christopher Crocodile' video that used to be Miss Muffett's.
'Doh!' I think that's Homer Simpson - who's been letting him watch 'The Simpson's'?!
And my favourite: 'Stop, in the name of Plod!' Don't know where that has come from but it cracks me up every time!