Childrens book about a boy who gets turned into a thing that looks like a penguin with no mouth

[Jason Hildebrand]

there is a boy who does something i forget what, and then he gets turned into this skinny frail thing with no mouth . he has eyes and his nose looks like an upside down triangle but no mouth

[Rainbowheart]

When did you read it?

Is this a picture book or a child's novel?