Rex disrupts the other toys blowing soap bubbles, worried that they may ruin Bonnie's house. He is chastised by the other toys, with Mr. Potato Head calling him "Partypooper Rex". The other toys sense Bonnie approaching, and scatter, leaving Rex alone when she enters. She takes him to play with while she takes a bath until Bonnie's mother comes to turn off the bath, pull out the plug and take her out. The bath toys are happy to see Rex, but soon the water gets drained, leaving them on dry land. Sad, the bath toys wish that they could continue to have fun, but all of them lack arms (except Rex) and can only function if afloat in the water. Rex initially thinks drawing a new bath is a bad idea, but after recalling Mr. Potato Head's insult, he asserts that he is "Partysaurus Rex", and helps the bath toys to start a new bath.