We all know that a Dreadnaught is a very old Space Marine that went above and beyond the call of duty during his regular service, but their body has been mostly blown to bits, so they're tossed in a giant robotic body to keep them in the fight. But what happens when a Librarian gets put into one of those? Well, you get something like the Thousand Sons Contemptor Dreadnaught, now available to order from Forge World.
From the release:
The perfect Elite choice for a Thousand Sons Legion army, the Osiron Pattern Contemptor Dreadnought retains the options available to other Contemptor Dreadnoughts while adding a psychic flourish to its capable offensive repertoire.Source