Skateboarding "walrus" style means that you push the skateboard either "goofy" (left foot on back of the skateboard and right foot in front) or "regular" (right foot on the back of the skateboard and left foot in front) but you ollie the opposite way that you ride. So if the skater skated "goofy" he/she would ollie regular and if the skater skated "regular" he/she would ollie "goofy".