The Japanese snowman is called 'yukidaruma' after the name of 'Daruma' (Bodhidharma), the founder of the Zen Buddhist sect. Yukidaruma is built with two snow balls when western ones are usually made of three. It has also no arms, no carrot noes nor broom.
External links :
http://celestialkitsune.wordpress.com/2008/12/25/the-origin-of-japanese-snowman-yuki-daruma/
http://www.examiner.com/japan-travel-in-national/the-japanese-snowman-yukidaruma