Sven Co-opedia Wiki

The Gene Worm is a large, tentacled alien life-form that serves as the final boss for the Opposing Force campaign. It strongly resembles the Xen Tentacle in both its color and its beak-like protrusions, meaning that the two must be related.


The Gene Worm emerging from the portal

It invades an abandoned sector in the Black Mesa facility through a dimensional portal, and players must work together to kill the creature before it fully emerges from it.

The Gene Worm spraying poison gas

It will attack players with its toxic breath and will lash out with its tentacles, but it can be temporarily blinded using the mounted laser guns on either side of the portal.

Once it is completely blinded, the creature will expose its heart and create a portal that will summon an enemy. The heart is its weak point and must be attacked with the lasers to damage it. This procedure must be repeated enough times until the Gene Worm finally dies.


  • Currently the Gene Worm is not officially supported for Sven Co-op: the monster_geneworm entity doesn't yet exist and otherwise will not spawn from the portal when approaching it, making completion of the level impossible- however you are able to use a custom entity script to function properly in your server. You can download it here.
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