Spook-E - Headcrabs

David Moscato (0:00)

You're listening to The Common Descent Podcast.

Will Harris (0:07)

And welcome to Spookulative Evolution. Hello, David.

David Moscato (0:13)

Look at me still talking when there's science to do, Will.

That's the only Valve game I've ever played. That's what I got.

Will Harris (0:24)

I like it. And hello, listeners. Welcome to episode three of Spooky 2026

This time we are with Headcrabs, our next alien for this year's theme of extraterrestrial monsters.

David Moscato (0:40)

Sounds like something you should get a doctor to look at.

Will Harris (0:43)

Yeah, no, and there is a doctor, we'll mention about that, that studies them. In this series, we have been investigating alien creatures from popular media and speculatively evolving, how something similar to them could evolve here on Earth under our real world natural selection and rules of evolution. This is just for fun, this is just to be silly, and we are doing it on Earth, because even though they're aliens, until one of us gets to go to another planet, we're gonna stick with the one we know. For this episode, we're doing Headcrabs, the famous monster, one of the main regular enemies in the Half-Life video game series.

David Moscato (1:32)

Yeah, it's been a fun journey so far this year of Spooky, because we did movie monster aliens, we did like real world conspiracy, pop culture, general zeitgeist aliens, and now we're in the realm of video games.

Will Harris (1:48)

Yep, this is a much more recent entry into our list. Headcrabs showed up in 1998, when the first Half-Life game was released, but they have been throughout the series, which is Half-Life 1, Half-Life 2, and then some in between and not yet sequel material.

David Moscato (2:09)

Yeah.

Will Harris (2:09)

Surely leading up to the inevitable Half-Life 3

David Moscato (2:12)

Any day now.

Will Harris (2:15)

Once that comes out with all the new Headcrabs that will be in there, we'll update this. So, keep an eye out for the update to this episode.

David Moscato (2:22)

We guarantee it. Yeah.

Will Harris (2:28)

Half-Life 3 update confirmed.

David Moscato (2:30)

Yes. Spooky Headcrabs Part 2 confirmed.

Will Harris (2:36)

The Headcrabs are kind of, they're like, they're the goombas of the Half-Life games and that, like, they show up quite regularly. They are not typically meant to be a big, tough enemy, but these are one of those where, in the right scenarios, if you get outnumbered and there are certain alternate versions that can become a major threat very quickly.

The Headcrab itself is a fairly small creature, described on the Wiki as about the size of a pumpkin.

So like a smallish, not quite medium sized dog is really the thing to picture with them. They've got four little legs. The front are kind of raptorial, like insecti, and the back are sometimes portrayed that way, but often as these kind of little stubby, powerful, more muscular legs. They have no discernible face. They have this just rounded, smooth, topped body with little mandibles up front that it's never clear if that how they use those. We don't know that they use those for anything in most cases. No visible eyes, though, in some older models, there did seem to be some eyes around the side of the mandibles.

David Moscato (3:56)

OK.

Will Harris (3:57)

Their main feature is on their underbelly, which has a large gaping mouth. And somewhere within there, a beak structure. This is what they use to do their most famous habit of leaping on to victims' heads, engulfing the head with that mouth, cracking into their skull to attach to the brainstem and take over their body as a vehicle for them to move about.

David Moscato (4:24)

Oh, OK.

Will Harris (4:27)

Yep.

David Moscato (4:27)

Cool. Like I said, have not played any of the Half-Life games. Didn't know that that's what they did. I didn't know that they took over the body.

Will Harris (4:34)

Yep.

David Moscato (4:35)

That's cool. That's great, because up until you said that, I was like, we did Metroids last year. Yes. Which would have been in this year's series if we hadn't done. That would have been this episode instead of Headcrabs.

Will Harris (4:47)

It would have been Metroids.

David Moscato (4:49)

I'm glad that you said that, because that makes them significantly different from the way that Metroids work.

Will Harris (4:54)

These are alien zombies, effectively driven by this smallish creature.

David Moscato (5:02)

Gotcha.

Will Harris (5:03)

These critters are also unique among our aliens so far, in that they are not actually from another planet, but another dimension.

David Moscato (5:12)

Oh, sure.