She only appeared at the beginning of the movie. She and Marlin were swimming down to their sea anemone where there were a lot of baby eggs. Marlin decides to name half of the kids Marlin, Jr. and half of them Coral, Jr., and Coral says that she wants to name one of them Nemo, so Marlin says that he'll only name one child, "Nemo." Coral was wondering why Marlin was looking at her the way he did, Marlin tells Coral about how they first met and she tried to get away from Marlin by swimming out of the anemone.
When Marlin swam out to find Coral, he saw her getting shocked as she stares at a barracuda. Marlin tells Coral to get back into the anemone, but then she rushed down to save the children from the barracuda. Marlin tried to fend the barracuda off, but then it slapped Marlin with its tail and knocked him out. With Marlin out of the way the barracuda moves on to Coral and their eggs.
After that, Marlin discovered that Coral and all but one of their eggs have been killed by the barracuda. Marlin found the last egg and named it "Nemo," to honor his wife, Coral's wish to name one of the children "Nemo."
"We're going to be parents!"
Coral staring at a big barracuda.
Coral fears for the safety of the eggs.
Coral dashes to the eggs and her death.
In the original storyboard of the film, it was shot so that the audience could glimpse Coral in the barracuda's mouth, but this was later cut, possibly because it might terrify young kids watching the movie. Because of this, Coral was killed offscreen.