What episode of to love Ru have the robot dog?

In the anime "To Love-Ru," the robot dog, named Peke, appears prominently in the episode titled "Peke's Secret," which is the 9th episode of the second season, "To Love-Ru: Trouble - Darkness." Peke is a unique character that adds comedic elements and assists the main characters throughout the series. His design and antics contribute to the show's lighthearted and playful nature.