Legendary Entertainment may have been promoting its Kong: Skull Island outdoor activation at Comic-Con International in San Diego, but the company's burgeoning MonsterVerse left its mark with a tweet from the fictional Monarch organization hinting at the arrival of Mothra.

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A "classified" image from "Temple of the Moth" in the Yucca Province reveals a relief of the Godzilla franchise's enormous moth-like creature surrounded by larvae, and what appears to be an egg or cocoon overhead.

Unlocked: Monarch Classified File #63061 – Temple of the Moth, Yucca Province – E. Russell #MonarchSighting pic.twitter.com/bCSAomvpCM— [MONARCH] (@MonarchSciences) July 22, 2017

Earlier this month Legendary teased Godzilla's other traditional opponents, Rodan (an irradiated Pteranodon) and King Ghidorah (a three-headed, dragon-like kaiju). In that previous clip, fans were treated to a marker on the timeline in 2009, also labeled "Temple of the Moth," but from the Yunnan Province in China, where Monarch discovered "a megalithic temple, within which lies a gigantic cocoon," and where "a quickening heartbeat is detected inside" -- hinting at either Mothra or the creature's offspring.

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Depicted in 2014's Godzilla and last year's Skull Island, Monarch is responsible for monitoring all kaiju activity on the planet. In the Skull Island post-credits, Monarch unveiled archival footage of cave paintings depicting Godzilla, Rodan, Mothra and King Ghidorah (below), hinting at the monster brawl to come in 2019's Godzilla: King of the Monsters, which will further set up Godzilla vs. Kong.

Godzilla: King of the Monsters will follow "the heroic efforts of the crypto-zoological agency Monarch as its members face off against a battery of god-sized monsters, including the mighty Godzilla, who collides with Mothra, Rodan, and his ultimate nemesis, the three-headed King Ghidorah. When these ancient super-species -- thought to be mere myths -- rise again, they all vie for supremacy, leaving humanity's very existence hanging in the balance.”

Arriving in theaters on March 22, 2019, Godzilla: King of the Monsters is a production of Legendary Entertainment directed by Michael Dougherty and starring Vera Farmiga, Ken Watanabe, Sally Hawkins, Kyle Chandler, Millie Bobby Brown, Bradley Whitford, Thomas Middleditch, Charles Dance, O’Shea Jackson Jr., Aisha Hinds and Zhang Ziyi.