Dumb Dumb and Gum Gum

We watched the Night Museum Part I and there is this big statute always telling the security guard "U dumb dumb, I want Gum Gum". Gar Gar picked up this phrase and went around telling people dumb dumb trying to scare them but ended up everyone so puzzled and asked me what is he talking about.

Then there is this scene about the HUN tribal who spoke the HUN language. Now Julian has picked up this language and alway converse with me, Gar Gar or the maid in HUN language. And Gar Gar is picking up too!