| image=FileCombine BM Pod.jpg|250px
| name=Combine Big Momma Pod
The '''Combine Big Momma Pod''',Playable Half-Life 2 Beta|''Half-Life 2'' Beta files also known as the '''Big Momma Birthing Pod'''http//www.gamespot.com/pc/action/halflife2/images/6112889/37/ GameSpot or '''Birther''', is a Combine device cut from ''Half-Life 2''.
FileAdvisors birther.jpg|The Advisors placeholder blocking the way in the Ravenholm caves.|150px|left|thumb
The name "Combine Big Momma Pod" comes from its model name, "Combine BMPod".
The Combine Big Momma Pod was used to create Headcrabs in huge quantities, this metallic structure was apparently to carry a Gonarch while it laid Headcrabs.
It was to be used at least in Ravenholm in a cave, blocking the way to the player while constantly laying Standard and Fast Headcrabs, and to be destroyed with the Digger (in a cave recycled in the retail map "d1_town_04"),Playable Half-Life 2 Beta|''Half-Life 2'' Beta and on the surface, in a double hangar located around the building where Father Grigori is first seen in the retail game.FileRavenholm overview2.jpg
It is possible that other Gonarchs were to reach Earth and subsequently be used by the Combine as portable Headcrab "factories". The metallic structure seems to pierce the sack, making the ''Half-Life 2'''s Gonarch the only "transheadcrab" creature, and some sort of "slave" Headcrab transformed in a beast of burden, in the vein of the Stalker.
FileRavenholm overview2.jpg|Early concept art including the Big Momma Pod on the upper-left.|150px|right|thumb
The only known model does not feature the Gonarch itself, but only its sack attached to the pod itself, and has no animations. There is no known Source Gonarch model, as in its only possible appearance three tied Advisors with a barrel in the middle are used as placeholders in the Ravenholm caves. They cannot be killed and will harm the player if they get closer. The player must noclip to proceed to the next map since the Digger does not work. It is also possible that there never was to be a Gonarch above the birther and that it was to have been modified by the Combine to operate by itself. The Combine Big Momma Pod never made it into the retail version, the Headcrab Shell filling the same role somehow.
==List of appearances==