Latest post in sidebar? (with image and opacity over the image!)

Hi everyone
I was just wondering if anyone knew what plugin I could use to achieve something like what this website are doing:

https://preview.tinyurl.com/c76ohb (indirect link in case they Google themselves!)

With a latest post from a category, an image from that post, a css overlay with opacity background and the title of the article on top of it – all going in the sidebar.

I’m struggling to find anything in the WordPress Plugins browser and have tried to Google various css hints from the site but nothing’s got me any closer.

Thanks in advance!