Penguin-like dolls from the Disgaea video game series, and other titles by Nippon Ichi. They are mascot minions. Prinnies explode on impact when thrown, dood. Prinnies contain the souls of humans or demons who lead a criminal life or committed a grave sin, and have to work in Celestia (Heaven) or the Netherworld (Hell) to pay off their debts and reincarnate as something else. It's stated somewhere that you also become a Prinny if you lead a meaningless life.
Prinnies slur the words at the end of their sentences as "~ッス", or in English localizations, say "dood" at the end of sentence, dood.
Kazamatsuri Fuuka is a notable "prinny" from Disgaea 4 who wasn't fully converted into a prinny, and instead looks and acts as a girl with a prinny hat on and doesn't explode, in spite of her technical prinny status. Other characters who die in Disgaea frequently reappear as prinnies, including some bad endings, but they are spoilers.
Voiced by Majima Junji.