There is only one file type that uses the .MD5ANIM extension:
id Tech 4 Model Animation File
3D animation file used by id Tech 4, the game engine used for Doom 3 and Quake 4; contains animation sequence data for a 3D mesh stored in a corresponding .MD5MESH file; saved in a plain text format; used for creating motions for game characters, weapons, creatures, and other game objects.
MD5ANIM files can be exported and imported using several 3D modeling programs that have the appropriate plug-ins, including Maya, 3ds Max, Blender, Lightwave, and Softimage.
Updated: May 31, 2015