Ever seen The Blob? This is sort of like that – only the blob doing the absorbing is a ball of putty, infused with millions of micron-sized ferromagnetic particles. The putty is nothing special on its own, but watch what happens when you stick it next to a powerful neodymium iron boron magnet.
YouTuber Scott Lawson explains what you're seeing:
The presence of the strong neodymium iron boron magnet (the silver cube in the video) magnetizes the ferromagnetic particles in the putty. When this happens, the ferrous particles align with each other and this alignment generates north and south magnetic poles, making the putty into a temporary magnet. Once magnetized, the putty will remain magnetized even after the rare-earth magnet has been removed from the putty. This effect persists for a few hours until thermal agitation shakes the particles and they lose their alignment.
The video was shot at 3fps over the course of 1.5 hours, and played back at 24fps. It's hypnotizing to watch – even if things do get weirdly sphincteral towards the end there. (We know you were thinking it.)
NOW IN GIF FORM!