Overlord X Golem Barbarian Crossover Story

Overlord X Golem Barbarian Crossover Story (オバロン X ゴレ蛮クロス小説) is a special crossover story by Mugane Maruyama of Overlord and Kitaichiro Ken, the author of Sorcerer King of Destruction and the Golem of the Barbarian Queen. It was released in the second volume of Sorcerer King of Destruction and the Golem of the Barbarian Queen as part of a limited time only special on December 27, 2018.

Main Summary
As the two adventurers, Momon and Nabe were on a journey together, they are caught within a strange fog that appears out of nowhere suddenly. There, they encounter Goree Taro who was dressed in his pajamas.

Full Summary
Momon and Nabe find themselves in a thick fog. The two are on a mission of exploration under the direction of Guildmaster Pluton Ainzach from E-Rantel. After two to three weeks the adamantite adventurers have been traveling with no end to the fog in the unexplored region that they find themselves in. The two complain about the visibility and contemplating using magic to assist them. However, they see the fog thinning out and bright red light. They see it is a fire and two people. One is a man holding mushrooms and the other a woman of a stellar elven woman. However, Momon notices that she is actually a golem. The campers are immediately wary of the newcomers. Momon introduces himself and Nabe. The two at the fire likewise give them names the man being Nemaki Dassé, a traveler, and his golem companion Kotaro. Momon is a little confused by the name, as in Japanese its similar to pajamas. He dismisses as a coincidence. He notes Kotaro and marvels at her construction, noting her to better than Luci★Fer's work. He compliments the golem, which Nemac then invites them by the fire. Momon is suspicious of their hospitality but decides to accept. The adventurers ask about the fog they encounter and wonder if the two have encountered anything strange. Momon is still on his guard but cannot ignore such a well craft golem is beside him with such independence. He wishes to acquire Kotaro for Nazarick but reminds himself he must be on alert. Seeking more information, Momon casually asks if Nemaki is a player, but the latter is confused by the phrase. Momon hastily explains its a term for people with dark-hair from the south in the New World. Before they could go further sudden shocks from the earth commence and the fog becomes thicker. A yak-like creature emerges from the fog, revealing it to be the source of the phenomena. Nemaki is impressed by the beast and believes it to be harmless contrast to its menacing stature and advisement from his campmates. Just as the yak attack, Kotaro swiftly intervenes and bashes the head of the beast with her fist. The scene stuns both Momon and Nabe, with the former estimating that Nabe would not stand against that brute strength. Nemaki chastises Kotaro for killing the animal. Momon decides that since the fog issue has been resolved its best to separate. Nemaki is disappointed but understands seeing that they are leaving due to his partner. The two adventurers leave discussing what they had seen, impressed at Nemaki's fearlessness and the ability of the golem. They decide to return to E-Rantel and report to the guild.

Trivia

 * This is the second crossover work to have been officially released in the Overlord series.
 * The story is split into two accounts by the protagonists of the respective series. One being Ainz Ooal Gown and Nemaki Dassé.
 * Judging by the story, if assumed to be canon, this takes place sometime after Volume 10, in which the Adventurer's Guild commits to more exploration expeditions at the insistence of the Sorcerer Kingdom.