Readers, beware. These objects are not from the faint-hearted – mummified fingers, beastly mermen figures and haunting dolls. Housed in museum collections around the world, they have now come to the social media surface thanks to an online challenge by the Yorkshire Museum in the UK. On Friday, the archaeological museum instigated a “Curator Battle” on Twitter with the inaugural theme “Creepiest Object”, challenging curators and specialists to find the most bizarre, hair-raising objects in their museum collections. Yorkshire Museum’s submission looks harmless enough at first glance, a hair bun from the third or fourth century, until you read that it has been taken from the burial site of a Roman woman. Museums – large and small, some with the most niche of collections – responded with pictures of odd and frightening objects, including a presumed Javanese ritual figure of a dried merman from London’s Science Museum. With a skeletal body and wispy white hair and feathers, the creature looks like a crossbreed of bird and fish. Art institutions were also keen to show off artists’ works, such as Kerry Jameson’s ceramic piece of a lower leg transformed into a monster with its own limbs and eyes. Meanwhile, a submission from a German museum seems fitting for the current times: a plague mask with a long beak-like feature from 1650 to 1750. For those who dare, the hashtags #CuratorBattle and #Creepiest Objects will uncover more nightmare-inducing treasures, such as a drinking bear toy from the Museum of Penshurst Place or the dolls at the Lilliput Doll and Toy Museum – objects that make you question how they managed to market them to children. The tweet continues to gain responses, with more than 500 replies and 2,400 retweets. Submissions have come in from around the world, including Germany, Canada, Iceland and the US. The next Curator Battle with a new theme will be announced on Yorkshire Museum’s Twitter page on Friday.