From Toontown Rewritten Wiki

An animation is when a Toon presents some form of physical action that is meant to show emotion. Animations are available in the "Animations" section of the SpeedChat menu. All Toons receive five of 21 animations upon entering Toontown for the first time. The rest can be purchased from Clarabelle's Cattlelog, excluding the Resistance Salute.

Some SpeedChat phrases can cause a Toon to use an animation; any phrase that uses an animation displays the letter e. Most animations cannot be used nor selected in the SpeedChat menu while the Toon is already in motion.