We transformed the Grand Ballroom into the coolest clubhouse ever!!!”
-- Lil' Petey (Lord of the Fleas, Chapter 1)

Importance: Lil' Petey has just shown Dog Man the changes he made to the ballroom, which is one of many rooms in Dog Man's doghouse. This shows that Lil' Petey is intelligent and mechanically inclined. The fact that he has created a club demonstrates his devotion to Dog Man. Dog Man approves, which demonstrates his devotion to Lil' Petey.

Look, kid – I'm not your Papa! You're my clone!!!”
-- Petey (Lord of the Fleas, Chapter 1)

Importance: This is Petey's mantra as he tries to deny the relationship that exists with Lil' Petey. Petey wants to remain the tough criminal, and Lil' Petey's presence tends to make that difficult.

Now that we've got you, we're gonna destroy someone you love! Your little clone!”
-- Piggy (Lord of the Fleas, Chapter 2)

Importance: Petey is recounting what happened that morning when Piggy was disguised as a psychiatrist. Lil' Petey immediately focuses on the fact that Piggy has identified Lil' Petey...