It is easy to see that there cannot be a proper holomorphic map from the punctured unit disk to the unit disk in the complex plane. What about the other direction; does there exist a proper holomorphic map from the unit disk to the punctured unit disk?



Proper holomorphic map from unit disk to punctured unit disk
I don't think so. A map $\mathbb D \to \mathbb D^\ast$ would lift to a map $\mathbb D\to \mathbb H$, where the upper halfplane $\mathbb H$ is seen as the universal cover of $\mathbb D^\ast$. As $\mathbb D \to \mathbb D^\ast$ is proper, so is $\mathbb D\to \mathbb H$. In particular it has closed image but by the open mapping theorem it also has open image and is hence equal to $\mathbb H$. That means that the inverse under $\mathbb D \to \mathbb D^\ast$ of a point is the disjoint countable topological union of non-empty sets which contradicts properness.


