No idea, never seen anything like that on a vehicle. Looks like someone lost the drain plug and improvised with whatever that thing is

Try to twist it out with some pliers, and replace with a normal plug. That one looks flimsy. I wouldn't be surprised if the the original threads are stripped though. It might need an insert kit.

You should be able to unscrew it by grabbing the lip with a pair of pliers or vise-grips and rotating it. Until it's out you won't know if the threads in the pan are OK or whether someone just jammed that thing in there due to stripping them out. I'd deal with it sooner rather than later.

You'll probably have to either helicoil the threads or buy a new pan. That's a hack job, to be sure