Final answer:
Custom animations in most presentation software are added from the Task pane.
Step-by-step explanation:
In most presentation software, custom animations are added from the Task pane. The Task pane is a panel that appears on the right side of the software interface and provides access to various tools and features, including custom animations. By using the Task pane, users can apply different types of animations to specific elements, such as text boxes, images, or shapes, within a slide.