| Clue | Source | Date |
|---|---|---|
| Porcupine features | Thomas Joseph | 11 Mar 2025 |
| Tail feathers | ||
| Porcupine cover | Wall Street Journal | 27 Jul 2024 |
| Old-timey feathery pens | USA Today | 09 Dec 2023 |
| Old-fashioned pens | Eugene Sheffer | 14 Nov 2023 |
| Porcupine spines | The Telegraph Quick | 27 Jun 2019 |
| Porcupine's protection | USA Today | 01 Jan 2018 |
| Porcupine's protection | ||
| Porcupine's barbs | ||
| Feathers used as writing pens |