Momoka, Mood of the Starry Sky / Keroro, Little Hair of Luck
When Momoka invites Fuyuki to an abandoned planetarium, he becomes possessed by the spirit of an old projector! Then, Keroro has a single wild hair growing on top of his head, which he cultivates after Fuyuki tells him it's a "lucky hair." Source: crunchyroll
Aired 25/09/2010EP 333 - Momoka, Mood of the Starry Sky / Keroro, Little Hair of Luck
Sgt. Frog
Keroro is a frog-like alien sent from his home planet on a mission to conquer Earth. But when his cover is blown, his battalion abandons him and he ends up in the home of the Hinata family. There, he's forced to do household chores and sleep in a dark basement that was once supposedly a prison cell haunted by the ghost of an innocent girl. He even spends his free time assembling Gundam model kits. During his stay, Keroro meets up with subordinates who were also stranded during their failed invasion.
(Source: Anime News Network)