| A | B |
|---|
| Mrs. Frisby | protagonist |
| Jenner | abandoned the rat colony |
| Nicodemus | leader of the rat colony |
| Brutus | sentry guard that will not let Mrs. Frisby in the rosebush |
| Timothy Frisby | Mrs. Frisby's son that has pneumonia |
| Mr. Ages | medicine maker |
| Justin | the first rat to figure out how to get out of his cage |
| Dr. Schultz | leader of the rat study at NIMH |
| Jonathan | Mrs. Frisby's deceased husband |
| Dragon | Mr. Fitzgibbon's cat |
| Jeremy | the crow that helps Mrs. Frisby |
| the owl | tells Mrs. Frisby to go to the rats |
| the shrew | Mrs. Frisby's neighbor that "protects" her house from the rats |
| Billy | Mr. Fitzgibbon's younger son who catches Mrs. Frisby |
| Toy Tinker | has a truck filled with tools and supplies |
| Isabella | a young rat who has a crush on Justin |
