If you want to share your stuff with us, you can either email creations [at] lambdageneration.com or just Tweet us, Facebook us or use our Tumblr-Submit page.
Lambda Pumpkin by CrowbarSka:

Wake up and smell the pumpkin
Another Lambda Pumpkin by itsmewallis:

Yet another by thealmightyshoe on Tumblr:

This insanely detailed carving of Lamarr the heacrab with the HL2 logo was done by DeviantArt user ravenousdarkhart. Trying to carve a 3D creature into solid pumpkin flesh has gotta be hard, but this has been pulled off perfectly.

Half Life Halloween by ravenousdarkhart
As you may expect, the Lambda logo is a popular symbol for Valve-fan pumpkin carving:

Half-Life Pumpkin by HmcdlNny
This one above was created by DeviantArt user ‘HmcdlNny‘. One of the troubles with the Half-Life Lambda logo is its circularity, which prevents an entire circle from being cut, so notches are needed to keep it in shape.
Below is another by ‘Kireek’, which apparently won 2nd place in NSider2‘s 2010 Pumpkin Carving Contest:

Lambda logo pumpkin by Kireek
Finally here’s one I found when searching around. I couldn’t find the name of the creator but this one, unlike the others somehow managed to carve the entire Lambda ring hollow.

Moving onto Portal, here are two incredibly detailed pumpkin carvings from the Joystiq pumpkin carving competition:

Michael’s Portal pumpkins
Below is another pumpkin from the competition by Cory Knapp of a faithful companion cube! It seemed though that this one either rotted or was turned into soup rather than being euthanized.

Cory’s Knapp’s Weighted Companion Cube pumpkin
ValveTime.net Halloween Costume Contest
ValveTime.net are currently running a costume contest for Halloween, offering you the chance to win a copy of Bioshock and Bioshock 2 with the Minerva’s Den DLC. As you’d expect, your submission needs to be Valve related.
To enter, you need to submit a photo of yourself wearing the costume to [email protected] (as an attachment) as well as info of your name, age, date of the photo, contact details and permission to use the photo on ValveTime.net’s site and Facebook.
For more info, check 5:15 of this video: http://youtu.be/QODOgoCLU_8?t=5m18s
Remember to send anything our way if you want to be featured on this post!
Team Fortress 2 Scream Fortress 2013
The annual ‘Scream Fortress’ event is now live. Check out Emil’s coverage of the event here.

You can share your (Valve and Halloween related) stuff with us by emailing creations [at] lambdageneration.com or by just Tweet us, Facebook us or Tumblr-Submit to us.
Oh, also we may try to put our Garry’s Mod server on some Gmod Horror maps tonight, that is, if we are not all consumed by the Scream Fortress event (Click here to checkout Emil’s article on this).
Happy Halloween!
Happy Halloween!