Our 8-pound dog is scared of our turtle.
Once upon a time, Raph the turtle was hanging out in our den and Rachel gave her a piece of banana. Chip the dog wandered in, saw the turtle and the untouched banana, and decided that, hey, Raph isn’t eating the banana and it’s on the floor, so it must be up for grabs. Before we could blink, Chip inhaled the banana piece and Raph… wasn’t happy. Apparently Raph was saving the banana for later.
Chip was startled that the turtle suddenly turned and really got going toward her. Despite popular belief, turtles aren’t that slow. When they wanna move, they move. Chip was still faster, of course, but she was startled enough to never want to stay in the den whenever Raph came out of her tank.
It’s a bit of an irrational fear. Honestly, there are no indications that Raph remembers the stolen banana piece or if she holds grudges. But seeing the turtle turn on her is ingrained in Chip’s little brain and makes the pup dash out of the room whenever she so much as hears Raph’s tank open.
Fears help round out characters. Even if they don’t impact much of the story, fears shape a character’s personality and actions. Facing their fears is usually a fantastic make-or-break moment for characters in their stories as well. Does your character’s fear help shape your character’s personality or the other way around?