Whaddupdoe- interj. v. (whad-up-dough) is a colloquial greeting for "what's up though?", "hello", "what's up?" "Peace!", "hey!".
Through relaxed speech methods, this terminology originated in the streets of Detroit circa late 70's, early 80's.
Whaddupdoe can also be used in both exclamatory and interrogative forms.
Let's create a scenario...
Person A- Whaddupdoe Cuzzo?!? (another formal Detroit greeting).
Person B and replies back by saying "Whaddupdoe?"