Repel Gels are rare items found in the game Paper Mario. The gel makes Mario invisible for three turns, making enemies attacks go right through him. They are a rather uncommon item, as they can only appear in a few select areas, such as Jr. Troopa's Playground after smashing the Stone Block there after Mario acquires the Super Hammer, in a ? Block in Gusty Gulch, and by paying Rip Cheato sixty four coins for the fourth time. They are also dropped by purple question mark Li'l Oinks.
In Paper Mario: The Thousand-Year Door, the Repel Gel was replaced by Boo's Sheet, which is a much more common item.