Crop Effect will be limited to a rectangle, with adjustments made to Top - Bottom - Right - Left.
To get a Shape, look into Track Matte Keying Effect, and create a Track Matte in the shape that is desired.
isn't there any way to use the titler to create anchors and make any shape you want? like if I wanted to trace around a keyhole or a person?
To crop around an image, instead of using a track matte, you might be happier with a garbage matte. If it is extremely detailed you might want the 16 point garbage matte. The 8 point is usually enough for most things and the 4 point for simple shapes.
The titler has full bezier curve controls. I don't have time right now to do a great job, but this was done with the pen tool - I did not make any curves because I don't have the time but I could have made the curves follow my head in a very accurate and detailed shape.
Now we're getting somewhere. so how do I use the bezier curve? how do i cut away everything but your head? how do I cut away your head and leave everything around in?
How to draw shapes with a curve:
When you draw your shape its a open bezier
when you are finished its a closed bezier
When you turn it into a shape to use as a matte for the track matte effect you change the Graphic Type to filled bezier and set the color to pure white.
If you need to animate the matte you place a garbage matte on a white solid instead of using the Titler. Unfortunately the garbage matte does not go beyond 16 points and no bezier handles.
You can feather a matte by adding a Fast/Gaussian Blur to the shape.