How does the AAY scare little kids?

[Bleems]

Just drinking blood from a big grown man in front of the kids.

[Reitavi]

By not doing much of anything. Her stature and girth is so intimidating, it can cause chickens to immediately drop eggs, convenient... yet unsettling.

[Colonial Custard]

"She doesn't have to do much, just appear in front of them. 'Course this works just as well on grown ups as it does on children."

[Maze]

Enslave their parents and older siblings. That mine isn't going to empty itself, after all.

[Bleems]

He just talk to the kids about very scary things even they are either not make sense or hard to understand.

[Winters Gate]

she sharpens her axe while watching them intently

[Bleems]

She does nothing wrong.

It just that some malevolent & scary supernatural beings keep following her, they are the real reason why kids are scared.

[kefkadragon]

By being big and strong. She just has to snarl at this point to scare them away.

[Bleems]

When he eats like this in front of the kids:

[By Lantern Light]

She flexes and they run away screaming.

[PixelPlays]

Standing up.

[Bramflan]

"Through shadow puppetry; those wings can help in making really creepy silhouettes."

[Delirium]

the ol' jumpscare from behind something, in this case, a tree

[pitbully01]

Showing them her "trophies," which are severed limbs wrapped in newspaper. They freak out and scatter right after.

[Bleems]

Just standing... with that BEAR.