Panda3D can load model files in formats like egg. However, text formats like egg can result in files of large size. Thankfully, Panda3D also supports loading model files if they are compressed.
The compression format that Panda3D supports is called pz. To compress and uncompress files into and out of this format, Panda3D ships with two programs: pzip and punzip.
To compress an egg file:
$ pzip foo.egg
To compress an egg file with maximum compression:
$ pzip -9 foo.egg
To uncompress a compressed egg file:
$ punzip foo.egg.pz
Tried with: Panda3D 1.9 and Ubuntu 12.04 LTS