| Name | Meaning | Gender | Origin |
|---|
| Maxine | greatest | Female | Latin |
| Maxwell | Capable
| Male | Scottish |
| Medusa | Guardian | Unisex | Latin |
| Monster | A creature of frightening appearance | Unisex | |
| Moose | Largest member of the deer family. Moose have heavy brown bodies with humped shoulders and broad antlers. | Unisex | |
| Morgan | circle; sea | Female | Welsh |
| Nacho | Small triangles of tortilla topped with cheese. | Male | Word |
| Nevada | Snow-clad. A western USA state.
| Male | Spanish |
| Oni | Japanese for 'demon' | Unisex | |
| Onyx | A gemstone with bands of different colours. | Male | |
| Opal | Australian gemstone of remarkable colours, usually red, blue or green | Female | Sanskrit |
| Opal | Australian gemstone of remarkable colours, usually red, blue or green | Female | Sanskrit |
| Oso | Bear. Oso for males and Osa for females. | Unisex | |
| Outlaw | A rebel or fugitive from the law. | Unisex | |
| Ozone | | Male | Hebrew |
| Pandora | talented one | Female | Greek |
| Pegasus | | Male | |
| Perseus | | Male | |
| Pixie | A fairy like creature. Playful and mischievous | Female | |
| Pixie | A fairy like creature. Playful and mischievous | Female | Swedish |
| Polaris | | Unisex | Hebrew |
| Pollock | pit | Male | Scottish |
| Primo | first one | Male | Italian |
| Puma | | Female | |
| Queen | A female sovereign | Female | Word |