User mypseudonymyoyoyo commented immediately with just one word, “Limescale.”

Another Redditor with the username xzxnnx wrote, “I would guess mineral buildup that broke loose in the tank. Take the tank lid off, and you may find a perfect match for the place where it came from. For sanitation reasons, toilets are designed to prevent things from coming back up, so the most likely source of this is the tank or dropped into the bowl by a human. Toddler humans are especially good for that.

They also imparted some important information: “Mineral deposits should fizz and dissolve if you drop a little bit of vinegar on them.” This is a great tip for anyone who might come across something like this in their own lives. Just to confirm whether it is limescale or mineral deposits, you can use vinegar to see whether it fizzes. If it does, then the doubt in your mind should be confirmed; it is indeed mineral deposits.

Other people agreed that it might be from the tank, limescale and mineral from water which might have collected over time, a redditor with the username badgersbunk added their two cents, “It looks like it came from the inside of the tank. I’ve seen a lot of tanks have something going up the corners inside and it does chip off when old.”

The original poster later added a comment confirming everyone’s suspicions, “I’m guessing it’s a chunk of mineral deposit and general sink/toilet debris that built up and dislodged in the drain pipe. It’s not really rounded like a pipe though and has more of a harsh bend. Picture taken on a standard envelope for scale. Pretty creepy seeing this in the toilet at 12 AM.”

All in all, it is pretty good for everyone to know what this could be in case you come across something like this in your own life!