In vase mode this needs to be printed with a large nozzle (> 0.8mm) with layer height about 0.3 or less, otherwise there is too much overhang in the neck area. With a smaller nozzle it might work fine with layer height decreased proportionately, but I haven't tried. In vase mode there will be a hole in the top of the head, see photo.
The author remixed this model.