Filibuster is a dog of the President. He is mentioned many times in "Mall Pups", but doesn't appear in any episodes.
History[]
In "Mall Pups", Lucky, Rolly, Spot and Cadpig learns that the first lady, along with Filibuster, will appeared at Mall for a book signing and plans to meet him. However, when Spot pointed out that they need to attend Bark Brigade class for their map reading lesson, but Lucky comes up with an idea; once they meet Filibuster, they will ask him for a presidential pardon in order not to get in trouble.
During the episode, Lucky and the others attempted to find Filibuster; unfortunately, it was too late as Filibuster and the first lady left the mall and headed back to the white house. To make matters worse, Colonel arrived (revealing that he knows Filibuster) and punish the pups and Spot for leaving during class.