From the episode "The Android Machine", after The Robot has bested Dr. Smith at Earth knowledge in order to be the teacher to Penny and Will, the Android VERDA interrupts him, asking him several questions about other planets which he is clueless about and asks if he can be a proper teacher to the children, he replies with:
The Robot:................I can lift heavy objects.
VERDA: Oh. I see. But wouldn't you think that a teacher should know about ALL subjects?
She snatches his pointer as the Robot rolls away dejectingly.
Later on in the episode, Dr. Smith is moaning that he doesn't like VERDA. The Robot agrees with him. When Dr. Smith asks why The Robot doesn't like her, his response is:
The Robot: She took my pointing stick.
The episode "Two Weeks In Space" definitly qualifies as one. Here, Dr. Smith tries making the Jupiter II into a hotel to make money quickly with himself as the manager, Will as the bellboy and The Robot as...every other single position in the "hotel".
From the same episode, when The Robot is complaining about all the jobs that he has to do: