Most fans of Marvel Comics are aware that Celestials are huge, but only by seeing them in comparison to the largest member of the Avengers do readers get a sense of how massive they truly are. Even casual fans who only follow the movies are aware of how big the cosmic beings are if they've seen 2021's Eternals. But the film doesn't convey their enormous scale quite like a scene from Neil Gaiman's and John Romita Jr.'s 2006 Eternals run.
The 2006 Eternals series tells the story of the main Eternals regaining their memories, and the awakening of the Dreaming Celestial, Tiamut. Tiamut's awakening threatens the wellbeing of humanity, so when it rises over San Francisco, of course the Avengers are there to try and save the day. However, the Eternals intervene to prevent them from doing something rash. Tiamut's power is so immense that even Galactus fears the Dreaming Celestial, but that doesn't stop the Eternals from scraping together a plan. Fortunately for Earth, Tiamut sides with humanity against his original purpose.
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In the first issue of this Eternals story, Ikaris exposits to Makkari about the Earth and its Celestial origins, and the ensuing flashback gives readers a glimpse of the size of the Celestials. In the foreground, prehistoric beasts flee out of a jungle in the midground, while the Celestials tower above the ancient flora, blocking out most of the sky. Fast forward to the sixth issue and readers get to see a double-page spread of Tiamut standing tall, and at his feet stands a tiny human form. That tiny human is actually Marvel's tallest human character: Yellowjacket (aka Giant-Man) at his fullest size, and the specks to his left are the Eternals.
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