An Office Worker Was About to Use the Toilet When This POPPED OUT! (PICTURES)

This is the stuff that NIGHTMARES are made of . . . and it's going to affect how every single person uses the bathroom from this day forward.

Stephanie Lasca works at a public relations company in San Diego. She went into the bathroom on the second floor on Tuesday, and was about to sit on the toilet when she noticed the water level was a little high.

Naturally, she assumed one of her NASTY lady coworkers had clogged the thing, so she took the plunger to it. And when she did . . . a GIANT SNAKE popped out and flicked its tongue at her.

So she ran out of the bathroom . . . probably screamed quite a bit . . . taped the door shut . . . and called Animal Services.

They came to the office, and found out it was a Colombian rainbow boa. By then it was on the bathroom floor, so they took it to a shelter . . . and it BIT a handler there.

They have no idea how it got into the second-floor toilet.

Here are some scary pictures