I recorded myself doing scary laughing using pitch bend, delay for echo effect and noise reduction. Recorded on conexant smart audio and at2020 usb mic, processed thru audacity.
Here is a super scary mashup of violins for your r-rated series!. This sound was made with the mick_gordon_string_efx. Sf2 soundfont. Here's the link: https://www. Polyphone-soundfonts. Com/documents/17-bowed-strings/286-string-efx.