From the Super Mario Wiki
Shiny Paragoombas are a species of Paragoomba that appears in Paper Mario: Sticker Star. Shiny Paragoombas look like normal Paragoombas, except that they have gained a shine to their body, have their defense at half, and more health and do more damage similar to shiny stickers. Shiny Paragoombas attack similarly to their normal counterparts. When Mario uses a Jump type Sticker or uses a First Strike and it still has HP left, it will be a Shiny Goomba. Shiny Paragoombas will also attempt to dodge Mario's hammer attacks by bobing up from the hammer making them difficult to defeat than most enemies and Mario should use the Hurlhammer sticker as they can't dodge this type of hammer attack.
Shiny Paragoombas also appear in Mario & Luigi: Paper Jam as rarer and stronger variants of Paper Paragoombas.