director: Unknown
year: 1907
country: France
history notes: Unidentified Film No. 171
alternative titles: Das tanzende Schwein, Lachen von Dunnemals, Lustiger Kintopp aus den Jahren 1904-1906

This film has been identified thanks to contributions from members of the Lost FIlms community.

No title. An actor in a pig costume dances on a stage [frame scan 1]. A woman takes his clothes off [frame scan 2]. The pig is embarrassed [frame scan 3]. The pig dances solo. Close-up of the grinning pig mask [frame scans 4 & 5].

Length: 40m
Format: 35mm, 1.19:1 (originally 1.33:1)
Picture/Sound: b/w, silent (with synchronised soundtrack)
Notes: Featured here as an item from the 1936 German compilation film "Lachen von dunnemals" (Laughter from way-back-when; Prod: Ferdinand Althoffs Historische Filmschau, Berlin; Dir: Friedrich Martin)

Source notes
Deutsche Kinemathek - Museum für Film und Fernsehen

This is the 1907 Pathe film Le conchon danseur (a.k.a. The Dancing Pig) - a favorite of Luis Bunel and one of the first films in the collection of the Museum of Modern Art.

Steve Massa is absolutely correct. A brief description of the film (in French) can be found in the Pathé filmography on the Fondation Jérôme Seydoux-Pathé website. The internet appears to be rife with video versions as well.