From the depths of glitchy alien heck comes the Zetan Poltergun, which allows you to take many of the NPCs in the game for a little player-controlled walk filled with lots of annoying camera oddities. It's kind of a throwback to the PS1 days in that regard.

Note: This, like the GrabbityGun mod, is a "just for fun" and proof of
concept mod that you can expect to be VERY glitchy.
I would use this like most odd cheat console commands are used on PC: on
a save or load where you are just messing around. It seems likely that
there are a few places you could get stuck pretty badly with this mod,
given that the camera workaround/hack requires moving the player around
like a phantasm. Use caution.

Regardless of if you've had the encounter yet, the gun can be found near
where the alien would be (on the ground in the UFO Crash Site cave
nearish Beantown Brewery and Oberland Station). Once you have the gun,
you can just shoot it at an NPC and try to move it around in the way you
normally move around. You should control the NPC for around 60 seconds,
and if you want to "abort" (jump out of the poor soul, you can spam
jump a bit).

Some notes:

At the moment, combat and hostility and alerting / jumping / inventory
management / sprinting / warping are not implemented.
Just a walk in the park (or submarine) type thing.
Alerted, hostile, or patrolling NPCs don't turn well at present.
Large NPCs, esp. will need some tweaking in-future (e.g. Behemoths /
Prime).
Believe it or not, there is a weapon mod.
Doesn't work on turrets, works fairly well on cows, eyebots, gorillas.
Currently: NPCs in animations, sitting will not be movable until they
desist.
Hills present a view/falling problem, since the LOS detection in-engine
is... idiosyncratic.
You can use it on multiple NPCs at a time, but the experience isn't pleasant.

On the PC (on some creature camera models), the TC console command trick
works much more acceptably within a limited area. The script extender
should also allow model replacement, which will lead to a more possess-y
kind of experience. But something like this is probably a good place to
start for goofy fun which doesn't exclude consoles.

Where is this thing?

The "UFO crash site" is roughly southeast of Oberland station, sitting over a rear hill bounding that settlement. Over another hill towards
Cambridge is the cave in which the gun resides. If the crash has occurred, you can follow the trail of (green) alien blood from the vessel itself. If the crash hasn't happened, I think there are still burn mark continuity errors which will lead to the nearby cave opening. The gun, bright red and white, is on the ground in the cave interior cell, in a nook on the left where the alien usually resides post-crash.