Animation menu: A hidden pop-up menu on the right side of many parameter rows in the Inspector. The Animation menu lets you perform animation- and parameter-related tasks: adding keyframes, assigning Parameter behaviors, managing rigs, and so on. To open an Animation menu in the Inspector, move the pointer to the right side of the parameter you want to animate and, when the downward arrow appears, click it.
For more information on animating parameters using options in the Animation menu, see Animation Menu.