You can search for free motion capture files (.bvh files), you can trim them in the free program bvhacker, and attach the results in fragmotion to a model .and export it to 3DGS.

http://www.puppenheim.org/
http://www.wuerfels-welt.de
Old Game Tutorial: http://www.puppenheim.org/MITutorial.zip
Free Game Editor: http://puppenheim.org/AlienalsWeihnachtsmann.zip
http://www.puppenheim.org/blender_starting_main_settings.txt