You can use a curve to do this. in order to make it into a tube you need to set the fill to full and raise the bevel depth and resolution. You can then animate the start value to control the end of the strip. If you need to scale up or down the ends, select a point on you curve and use Alt-S.
To animate, the start value hover over the input box and it I to add a keyframe. The navigate to the other end of your animate, set the value down/up then hit I again to add another keyframe. Keyframes can be remved with Alt-I.
The green lines in this gif were created using this technique in blender
Single image with settings
Green squiggles file: