Kigurumi is the Japanese name for costumed characters, it is generally performed at malls, theme parks, and promotional booths at anime conventions.
Kigurumi is a form of masked cosplay, preformed by hobbyists called dollers. Its currently most popular in Japan, though its quickly gathering steam in other areas, including the United States and Canada.
By wearing a mask, kigurumi cosplayers are able to get as close as actually being an anime character, is as humanly possible. The mask lets them free themselves more than they could in a normal cosplay costume, letting them slip mentally and physically into the skin of a fictional character.
This form of cosplay generally concerns a person in character-themed costume, in kigurumi, the actor, playing a humanoid anime character, will wear a flesh-coloured body suit and matching facemask, in order to better resemble the character in question. The body suit allows them less-detailed skin features, and the mask allows anime-style facial features.
While many cosplayers have costumes of established characters, many more have created their own original personalities.
Many people find the concept of life-size, 3D anime characters more than a little disconcerting. It's popularity in Japan resides mostly with adult fans, unlike the professional form of kigurumi, that also interests children.
Like with normal cosplay, many dollers wear their costumes at anime conventions.