I Second That Emotion (Futurama)

Leela is distraught at the loss of her pet and wishes Bender could understand the emotions of others.

Professor Farnsworth proposes a solution: installing an empathy chip in Bender's head that will cause him to feel other people's emotions.

After a night of experiencing a multitude of Leela's feelings, Bender misses Nibbler so much that he cannot stand it any longer.

When the chip is taken out the Professor says in amazement that it burned out, meaning Bender's feelings of empathy for Leela were his own.

Maurice LaMarche, former MADtv castmembers David Herman and Phil LaMarr, and King of the Hill voice actress Lauren Tom, however, remain as guest stars and stay that way for the rest of the series until Season 6 in 2010.