On 28 July 2010 it was announced that he would direct At the Mountains of Madness by H. P. Lovecraft for Universal Pictures, with James Cameron as producer. The movie was originally set up as a project at DreamWorks in 2004.[30] Just a month earlier, del Toro said that the Lovecraft adaptation probably wouldn't happen at all; "It doesn't look like I can do it. It's very difficult for the studios to take the step of doing a period-set, R-rated, tentpole movie with a tough ending and no love story. Lovecraft has a readership as big as any best-seller, but it's tough to quantify because his works are in the public domain." Not long after, he was approached by Cameron who asked him if he still wanted to do the movie. When del Toro confirmed he did, Cameron said “Let’s do it.” Both of them put forward the idea for Universal, which then greenlit it.[31] Earlier the same year, del Toro also asked S. T. Joshi if he wanted to be a consultant if and when the movie got into motion.[32] It was rumored that del Toro was approached to direct the new Godzilla movie produced by Legendary Pictures, which he later denied.
Mountains of Madness was not greenlit by Universal Studios, so del Toro's next directorial effort will be the giant monster film Pacific Rim, based on a screenplay by Travis Beacham, which was mistakenly rumored to be the basis for Legendary Pictures' Godzilla reboot, which del Toro was rumored to have been was approached to direct but later denied. Del Toro described the monsters in the film to be "Huge". The film involves giant monsters traveling through a vortex in the pacific rim where they attack major cities and humans must battle them by using mecha suits called Jaegers. He comments,"This is my most un-modest film, this has everything. The scale is enormous and I'm just a big kid having fun."[33]