The Ragnar piercing is a local term for a "deep snug" piercing; sort of half way between a snug piercing and a transverse lobe piercing. As you can see from the picture, the jewelry enters the body inside the ear roughly where a snug would start, and then exits on the edge of the lobe/helix.
Because this piercing travels through a great deal of cartilage it is at risk for complications such as ear collapse and attention should be paid to taking good care of it both during healing and after.
The first known photos of this piercing using this name were published in 2002. In this case the piercing was done by John Lopez on Thure Ragnar Stedt (shown above); hence the name.