Ayaka tried to endure the terror and still keep thinking . . . until she saw Saber and the police officers being looking around and realized that her brain was not the only thing shaking.
“? . . . What?” She muttered suspiciously just as the soles of her feet began to clearly feel the earth pulse.
“A-An earthquake?!”
No, not an earthquake.
Something’s coming toward us . . .
Then . . . as the vibrations grew steadily stronger, “it” emerged from behind a building.
An enormous, pitch-black dog, easily over fifteen meters tall.
Its entire body gave off a miasma-like smoke, and black flames, the same color as its coat, perpetually dripped from its jaws—the jaws of the three-headed monster blessed by Hades.

Fate/Strange Fake: Volume 6, Chapter 18 ("As Dream and Reality are Both Illusion I")