The swamp strider was a vehicle used by Mazeka.
When Mazeka piloted his swamp strider through the Karda Nui swamp, the vehicle moved quickly across the water. Magnetic force from the tips of its legs kept it aloft a few inches above the surface of the swamp. The swamp strider had skyblasters.
There was apparently more than one swamp strider, as Vultraz recognized "the distinctive outline of a swamp strider" when he spotted Mazeka in Karda Nui.
The swamp strider did not fly.