Finding legally downloadable PDFs of Homer's 'The Odyssey' as a graphic novel can be a bit of a journey itself, and you really need to watch out for the right source. Many sites offer downloads, but quite a few are unofficial scans of physical books, which obviously isn't legal or supporting the creators.
Your absolute safest bet is to check the publisher's official website directly. For the version by Gareth Hinds, which is incredibly popular and well-regarded, Candlewick Press is the publisher. They don't typically offer a full PDF for free, but they might have sample pages or a preview. For a full legal download, you'd likely need to purchase a digital copy through an authorized retailer.
I'd head straight to platforms like Amazon Kindle, Comixology, or Google Play Books. If you search for 'The Odyssey Gareth Hinds graphic novel', you can buy the digital edition there. You're not getting a PDF per se—it'll be in a DRM-protected format for their apps—but you own it legally. Your local library's digital service, like OverDrive or Hoopla, is another fantastic route. You can borrow it, and the app often lets you download for offline reading, which functions just like having the file. That's probably the most straightforward and ethical path.