Examples from Viking artwork:

Bridle mounts (the one on top right and bottom left):
http://www.archeurope.com/index.php?page=broa-oseberg-style

My personal favorite is the Gosforth cross. From the caption: “The Gosforth Cross, Cumbria, c900. The carvings on the cross depict a number of scenes from Viking mythology including Vidar attacking the Fenrir wolf and Thunor fighting the World Serpent.”
http://www.heritage-images.com/Preview/PreviewPage.aspx?id=2358838&licenseType=RM&pricing=true&from=search&back=2358838

http://midgleywebpages.com/pickcross.gif (this is a photo of a tenth century Viking grave marker (front and back) in Middleton, North Yorkshire) main site: http://midgleywebpages.com/thedanes.html