1x21 - Arthur

Viewers are taken back, as Arthur and D.W. recollect what happened when Baby Kate was first-born. D.W. is excited with anticipation, but Arthur is very worried. His worries are only made worse when his friends tell him about all the awful stuff that's going to happen when the baby comes. Still, Arthur, is determined to be a good big brother, but ends up thinking that the baby hates him!