He debuted in a series of Flash animations (mostly without any dialogue, although the occasional word of Korean or English is present) on the internet.

Mashimaro merchandise can be found on the internet and in Korean communities around the world.

The original Mashimaro cartoons are full of toilet humour, which can also be found in some of the merchandise.

When this character was first designed, multiple directors decided not to use him because they believed "cartoon characters must have big eyes and positive attitudes", in contrast to Mashimaro's thin eyes and pessimistic attitude.

Creator Kim Jae In created a series of flash animations on an internet cartoon site, which gained popularity.