When Ms Trunchbull pays a visit to Matilda's class the first time, Matilda's friend puts a newt in the pitcher of water meant for Ms Trunchbull. Ms Trunchbull pours herself a glass of water, and the newt ends up in the glass. She then starts drinking, and continues to do so for quite a few seconds, yet when she puts the glass down (still with the newt in it) the water level in the glass hasn't gone down.