The Legend of Sigurd and Gudrún claims that he desires only to avenge his father. The gold and the glory, he adds, are for Sigurd to keep. Twice Regin attempts to forge a sword for Sigurd, only to see the latter effortlessly break them. At last, Sigurd goes to his mother Sigrlinn and requests the broken pieces of Grímnir. Regin takes these and forges the sword Gram. Although Sigurd wishes to slay Fafnir then and there, Regin tells him he must have a horse. In response, Sigurd buys the horse Grani, who was sired by Odin's eight-legged steed Sleipnir, and goes forth to kill Fafnir. Later,
Legged robot tripod. Four-legged robots also benefit from a lower center of gravity than two-legged systems. Four legged robots include: Six-legged robots, or "hexapods", are motivated by a desire for even greater stability than bipedal or quadrupedal robots. Their final designs often mimic the mechanics of insects, and their gaits may be categorized similarly. These include: Six-legged robots include: Eight-legged legged robots are inspired by spiders and other arachnids, as well as some underwater walkers. They offer by far the greatest stability, which enabled some early successes with legged robots. Eight-legged robots include: Some robots use a combination of legs and wheels.