I mean, honestly.
Ah Dah: Mickey (coined from the "Hot Dog" song)
Wa Wa: Water or Walk, depending on the context
Mo Mo: Milk
Ma Ma May: Made a Mess (this one is actually our favorite - he uses it frequently. Because he frequently makes messes. But he uses it with such a serious tone, and the ever so slightest twang on "may." Ha!)
Ahjee: Ice Cream
Doe Doe: Kirkwood (which is fascinating, because that's what Owen called him, too!)
I'm certain there are more, but these are some of the first that come to mind.
He also has a plethora of words that are a little closer to their actual pronunciation, and does an amazing job of repeating after someone.. as long as it's something he wants to do. Toddlers. His vocabulary is just exploding. Love watching our second born learning to communicate with words!