 Groening thought that it would be funny to have a baby character that did not talk and never grew up , but was scripted to show any emotions that the scene required . Maggie 's comedic hallmarks include her tendency to stumble and land on her face while attempting to walk , and a penchant for sucking on her pacifier , the sound of which has become the equivalent of her catchphrase and was originally created by Groening during the Tracey Ullman period . In the early seasons of the show , Maggie would suck her pacifier over other characters ' dialogue , but this was discontinued because the producers found it too distracting . 
