Mary Ann Mobley who plays Arnold's teacher and Mr. Drummond's love interest would later go on to play Mr. Drummond's wife in the final season.
First appearance of Arnold's friends Dudley (Shavor Ross) and Robbie (Steven Mond) who will be recurring characters in the series.
When Arnold places a can (containing a pop out snake) on the teacher's desk, it would startle his teacher, causing the whole class to get punished. The prank would resurface in "Substitute Teacher" in which Arnold and Dudley almost costed a substitute teacher (Kareem Abdul-Jabbar) his job (from accidentally striking Arnold after being startled in a similar way).