12V Incandescent Lamp Ideas

While I am confused as to why it doesnt matter since it is your question. However you may have a hard time finding an incandescent with a standard base in that low of wattage. Other type bases you should be able to find one.

you might try looking here https://www.1000bulbs.com/category/incandescent-light-bulbs/?gclid=Cj0KCQjw9ZzzBRCKARIsANwXaeIogvRI6bV_b1RZsNlmutYKAxaTmjWNuYeEERVG6he_Ga3TlfeQUlIaApgNEALw_wcB

There are quite a few LED lights with a usb tail such as here
https://www.walmart.com/c/kp/usb-lights

I know this isn't what you are asking about but it is small, portable, rechargeable via usb and can put out a fair a amount of light
https://www.fenixlighting.com/product/fenix-cl26r-rechargeable-lantern/
I have a couple of their flashlights and they are awesome and rechargeable and you can buy an extra battery if you like the size of a AA type so you can always have an extra charged one around.

Any particular reason you want an incandescent bulb versus LED?

I went on Amazon and there is an USB powered gooseneck desk lamp/clamp on light. But it’s LED.