Another sound effect. This sound is completely free, which means you can use it for whatever you want. If you do use this sound on something like a game, please mention my name (you don't have to, though).
Some c0 16. 35hz sine drawed in audacity with mouse hand free with no correction of the irregularities, looping, an envelope drawed manually as well, like for the original graphical pixel art obscur principles, except some slight eq filtering.
Quiet bubbling punctuated by some groans. Recorded with a google pixel xl, as its bottom-facing (mono) microphone is perfect for this. No noise reduction.
Recorded a friend getting yelling in slow motion, ended up sounding like some sort of huge monster/creature roaring. Recorded on google pixel 3xl. Feel free to use.
Quiet bubbling and groaning on an empty stomach. Recorded with a google pixel xl, as its bottom-facing (mono) microphone is perfect for this. No noise reduction.