How do you type a character with its ASCII code?

I need to type the form feed character 0x0C in ASCII on my Mac. Is there any way to do this? I've tried using "Emoji and Symbols" from the Edit menu, but it's not in there.

It's there for me in Character Viewer (Emoji & Symbols, expanded version). It doesn't have a glyph, but if you double click it should be inserted. (Sometimes you may need to drag and drop to add.)

Note that you may have to go to the gear wheel at top left and select Customize to add the Unicode category. The Unicode category is under Code Tables.

Add Unicode Hex Input as your Keyboard. Hold the option key while typing.

If you like to use the terminal, you can do this:

printf "\x0c" | pbcopy

This pipes a single formfeed character to the pbcopy, which stores it in the system clipboard. You may then paste it into whatever app you need.