I'm not sure, as they didn't post it in the DLC section or any of the main game level sections.
In any case, in the DLC, the ice pencil is the last pencil you'll find and it will be in the in the very Northeast of the map.
In the main game, the ice pencil is found in level 6. You have to draw an egg in a nest on the mountain and find the feather at the base to get the bird to come pick you up.