Make your own call-out - draw it yourself (5)

If you are familiar with the drawing tools in PPT you can create you own call-out, here's a sample:

Follow the steps.

First step - draw your shape using the FreeForm tool. 

This is how it looked:

Second step - adjust the shape to give it its round corners.

To do that, right click on the shape - choose Edit points - click on the point you want to adjust - then use the handles to modify.

Third step - apply a shadow

Select the shape - Format - Shape effects button in the Shape styles group - Shadow - Inner- Inner middle.