Fuyuki, Butterfly Person Appears? / Giroro, Uninvited Guest
Fuyuki's excited when they find a Mothman-like creature in the forest. Then, an uninvited "guest" appears: a deserter from the Keron Army! Source: crunchyroll
Aired 18/09/2010EP 332 - Fuyuki, Butterfly Person Appears? / Giroro, Uninvited Guest

2004
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)