Readers can be pretty enterprising when they don’t have a bookmark handy. You’ve probably held your place in a book with a receipt, postcard, or, if you’re a weirdo, a slice of bacon.

One poetry aficionado in Pittsburgh, though, improvised in one of the creepiest ways possible: by using a dead snake in a plastic bag, Yahoo! News reports.

The bizarre bookmark was discovered by a woman who had checked out a poetry collection, Brenda Shaugnessy’s The Octopus Museum, from a Carnegie Mellon University library.

“So, um...weird question: is this your snake??” tweeted a professor named Joey Neilsen. “My wife checked out a book of poetry from @CMULibraries and it came with a snake in a bag.”

The Carnegie Mellon Libraries’ Twitter account retweeted Neilsen, adding, “Maybe it was a hissstory book? (please don’t put snakes in books).”

Twitter users were variously delighted and horrified by the discovery, with one tweeting, “Get these mo**er fu**ing snakes out of this mo**er fu**ing book.” Another chose to look on the bright side, writing, “Better than bacon, especially since it is nice and tidy in a ziploc.”

The library says it’s looking for the snake’s owner, but would prefer readers use other things to mark their place. (Though if you insist on using something reptilian, you can always learn how to make a snakeskin bookmark of your very own.)

Michael Schaub is a Texas-based journalist and regular contributor to NPR.