This can only be used on projectiles and makes them slither horizontally. The exact behavior depends on the frequency with which this function is called. You have to call this function repeatedly to have a permanent effect.
This function can be duplicated in a more generic way with A_Weave(3, 0, 1.0, 0.0).
Spawn: CSSF DDEE 1 Bright A_CStaffMissileSlither Loop