How to make your character unanimated
From Legacy Roblox Wiki
If you notice, your character moves its limbs when you walk around. This is called animation. Before January 9th, 2007, characters didn't have animation. A person's character would just move without its limbs moving. This animation was added to make the character appear more life-like. Along with the update, there has been an option that lets you decide whether you want to have your character animated or not. And even more recently, they deleted the non-animation all-together. So now you must stay with the animation.