Help identifying this beastie

My colleague found this on a walk in Vienna, and for the life of us we can't figure out what it is.

He claims it was one single creature, not two fighting or mating. He also saw it walking a little before he started recording. He uploaded it to TikTok too, but the comments there are as useful as a chocolate teapot.

To my knowledge, no insect or arachnid in Europe can get this large, but admittedly my knowledge is limited.