After the holidays, Humphrey is shocked by a big surprise in Room 26-a new class pet! Humphrey tries to be welcoming, but Og the frog doesn't respond to any of his friendly squeaks or visits (remember, he has a lock-that-doesn't-lock). Plus, the students are so interested in Og, they almost stop paying attention to Humphrey altogether. Humphrey doesn't like the mad-bad-sad feelings he's had since Og came, but luckily he still gets to have adventures with different kids on the weekends.