New words

You have to have a toddler-to-adult translator, but...

nein
nose
ear
eye
goose
hippo
gross
hot dog
Steve
Carol
I love you (more like I yah yah)
more (old word, but now accompanied with ASL)

Also noises:
Perry the Platypus's growl
rooster's crow

I know there's more. The big thing is, you ask him to try to say something, and he usually gives it a shot. Pretty cool.