Informally, it's known as the Nexogon.
Bricklink calls it "Plate, Modified 6 x 6 Hexagonal with Pin Hole". The part number is 27255. It's original use was as a shield in the Nexo Knights line in 2017, but it has appeared in a few other sets since then.
If you're interested in ways to use this part, New Elementary did a whole series of posts from different ...
What you are seeing is actually the result of poor lighting, somewhat worn bricks, probably camera app noise reduction, and perhaps image compression, although if you look really closely you can kinda see it's a little darker where the lettering is.
As the creator, I promise that every piece in the hat is 100% genuine LEGO pieces (no knockoff brands). ...
Check for visible part numbers
This usually only works if you have the physical part in front of you.
Look for a 4 or 5 digit part ID on the element. These are usually printed on the inside. A magnifying glass and good lighting can be helpful. Many bricks will also have other numbers printed on them, but only the 4 or 5 digit numbers are useful for ...
Hooray, I get to answer a question!
This is not a piece for launching missiles. It's actually part of an old steering assembly from some late 80s and 90s Technic sets.
Here's what the whole thing looks like:
And a view of the piece in question:
And an example of how it is meant to be used:
The teeth on the outside of the piece help lock it into one of ...
It's been worked out by multiple groups who decided on different systems. The disagreement is based on what information was publicly available from the Lego Group at the time, what pieces had been manufactured up to that point, and what features the category authors thought were salient.
To really appreciate the magnitude of the problem, just try ...
That looks like 30384 Windscreen 7 x 4 x 2 Round. In general, BrickLink is a pretty decent place to browse around for parts identification. Peeron is also pretty good.
BrickLink provides a comprehensive list of windscreens both plain and decorated.
These came from a number of sets, including a handy "Decorated Elements" set that covered most of the printed parts from the mid-90s space theme.
However, Recon Robot appears to be the only one that contains two of the 2x2 tiles and only one of the 2x1 tiles.
Instructions can be found in a number of places, including on Let's Build It Again.
The LEGO Pick A Brick store lists them as connector pegs (or, more simply, pegs) although they are more commonly known as pins in the fan community1.
The black ones have added friction for holding things together, while the light gray and beige ones are smoother and allow pieces to rotate, for example tires or beams.
1 BrickLink, Peeron
The part in question shows up as a "Minifig Gravity Stunt Handle" (part number x817) on Peeron and a "Turntable Spinning with Sports Trick Handle" (item number bb128) on BrickLink. Looks like it appears in two sets:
Snowboard Super Pipe:
Skateboard Vert Park Challenge:
It's 99563 LegoMinifig, Utensil Gold Ingot (Bar) in Light Bluish Grey.
Originally used for Gold pieces, nowadays regularly found as bricks and other wall decorations, for example on the ground floor of 10251 Brick Bank.
There are no LEGO parts with studs that have no logo on them. The hollow versions of studs which are on technic bricks and many other bricks have the Lego logo printed on the insides.
As someone that goes through a lot of used LEGO, I have found that there are some parts that have been worn and the logo is not nearly as visible as it would be brand new. ...
They are referred to as "Minifig Hips" almost everywhere: [partlink:970:4].
The LEGO Pick-a-brick service doesn't sell them without legs, and just refers to the whole construction as "Mini Figure Mini Lower Part":
According to the LEGO customer service, this part is a "BUSH Ø7.84" (which is of no help whatsoever, as with most LEGO internal names) and has the design ID 6221. Unfortunately, there seems to be no official picture for it yet.
This design ID corresponds indeed to the part which Joel Cohen and BradC have identified; the element id of the same part in black (...
It's difficult to tell exactly what part this fragment came from, but it looks like it is part of a broken Technic gear or pulley. It looks like it probably came from 3736:
Your fragment looks like it was probably once one half of the center axle hole of that part.
In terms of repair, I suppose you could try to glue this back together, but given that the ...
I think Joel Cohen's comment is correct, it looks like a "Technic handle/hub" (escalating to an answer so I can include pics):
Here's a similar-looking view from the parts list of set 7703 Fire Vulture:
and a portion of the instructions from 7476 Dino Attack that shows how it is used:
So if this is correct, it appears to be a mistake (or misprint).
From this image, you can count the teeth well enough to determine there are actually 60 teeth, not 40:
This does not appear to be a real part.
It also appears you aren't the first to notice this. Jim Brickkeeper has created a ShapeWays model based on this movie piece which I found while searching for LEGO 60 tooth gears.
According to Matthew Ashton this ...
Those horses look like legit LEGO-brand horses.
White Horse with Black Eyes, White Pupils and Dark Orange Bridle Pattern: 4493c01pb04
Black Horse with Black Eyes Circled with White, Brown Bridle Pattern: 4493c01pb02
In order to be extra sure they are genuine LEGO, look for the "LEGO" stamp on the inside of the hollow studs on their back ...
I've never seen that part until now, and it's certainly not in the antenna or bar bricklink categories. I'm fairly confident it's not LEGO.
However, it would be far more interesting to know what it is, but that's not easy to search. A few Mega Bloks parts have been catalogued, but your part isn't there either (I could only check categories bar, weapon and ...
You were on the right track. This is a skateboard, but it is not a LEGO part. It's a Mega Bloks part, probably from set 9167 (X Mountain). The skateboard in the top right has a sticker that seems to match your description.
The wheels clip on to allow them to pivot back and forth. I can only assume that this is to give these skateboards a more off-road feel.