Webster is a friendly spider, who is good friend with Team Umizoomi, but he has a stronger friendship with Geo since they both love shapes. His favorite shape is an octagon (with eight sides).
Webster lives in the Umi City Park, but he sometimes heads down manholes to play on the bouncy spiderwebs down there.
Webster is always to help Team Umizoomi out.
In "The Kite Festival," he showed Team Umizoomi what an octagon looks like when they were looking for the octagon piece of Jeannie's kite.
In "Meatball Madness," he gave Team Umizoomi instructions of a way of the inside of the manhole when the Trouble-Makers trapped them there. The manhole has bouncy spider webs. Geo used his Shape Magnet to reach the webs, and they all got out of the manhole.