Quake 3 Quad Damage model.. it has a floating / spinning idle animation identical to Quake 3 Arena.
Check out the Quake 3 Arena mod project for CS1.6 here : http://gamebanana.com/projects/34995
And if you're interested in working in the project developing models or maps. Contact me and i will further explain the mapping tutorial for the mod to you. Thanks and Enjoy! -Sneaky.amxx