Definition: Personification is a figurative device that is used to give an inanimate object, concept, or idea human-like emotions or qualities. These non-human things are given the ability to feel and think as if they were human beings, and this literary device helps the reader associate the actions of the objects to human emotions. Frequently, human characteristics are compared to natural forces (seasons), and feelings such as love, loss, pain, etc. Personification contributes to the emotions being expressed in the diction to resonate similar feelings towards the reader for rhetorical emphasis.
Example: "Have you got a brook in your little heart? Where wishful flowers blow, and bashful birds go down to drink. And shadows tremble so?"-Brook in your little heart by Emily Dickinson. Emily personifies having a brook in a person's heart, implying a heartache or loss of a loved one.
Dory and Nemo are personifications because they have human personalities and emotions.