Pepi

Pepi is a poor boy who became Homer's little brother.

History
Bart signed up with the Bigger Brothers Agency and was assigned to. In revenge, Homer signed up as well and was matched to Pepi. He and Pepi took an instant liking to each other, with Homer being impressed by Pepi's respectful behavior and Pepi being impressed by Homer's knowledge, even though some of the things Homer told Pepi were complete nonsense, such as that whales were not mammals.

When Homer and Tom got into a fight, Homer was injured and hospitalized, leaving Pepi without a bigger brother. Bart saw that Pepi was more deserving of Tom than he was, so he paired them up. Tom and Pepi were seen walking off into the sunset, while Bart was left to patch things up with Homer.

Pepi stayed in Springfield, and eventually ended up attending East Springfield Elementary School and living with Bumblebee Man. A head injury left Bart able to speak only Spanish, and he was sent to East Springfield Elementary, where he met Pepi again. He and Bart became fast friends, and Pepi invited Bart to his home and said that Bumblebee Man was "mi papa nuevo", indicating that Bumblebee Man had either adopted him or was his new foster parent (it isn't clear which situation was the case). When Bumblebee Man became outraged that the weather girl on Channel 8 was too sexy, the three of them went to a match.

Non-canon
He was seen in Springfield.