This site hosts fan-created content for the Zombicide "classic" line of games (a.k.a. "Moderncide"). The top menu of the site contains the links to the various bits and pieces.
This site's "crown jewels" are the print-and-play custom card decks which are intended to add some fear/loathing/humor/tension to your games by giving certain standard zombies and/or Abominations special abilities. This idea was taken from the 2nd-edition Kickstarter campaign, which gave each new Abomination a special ability and suggested "optional house rules" for the Kickstarter-exclusive zombie minis. (For example, the "swimmer" mini, because he's encumbered by his arm floaties, is easier to escape from.)
In addition to the (meager) documentation found on this site, there is additional documentation related to the card tools, as well as PDF-format exports of the cards (though possibly not the latest) in this GDrive folder.
To print cards, simply visit one of the card-based pages and use your browser's print feature (or "save to PDF", if you're using Firefox on Android). If you have the option, print them at 300 DPI or higher for the best results (600+ DPI looks quite professional, but 300 suffices). Printing them at 150 DPI will work reasonably well, but they'll be notably less crisp than 300 DPI. Printing at less than 150 DPI is not recommended.
There is still one important detail to be aware of...
The Zombicide cards are "US mini" size (41x63mm). This site can show the cards in two sizes: "mini" and "maxi". "Mini" size is the standard card size, but they can, due to small text, sometimes be difficult to read on average LCD screens. In "maxi" mode, cards are rendered at double their intended size, which makes them more readable on the screen but is not intended for printout. So...
The printing systems in modern OSes offer the ability to scale printouts. When printing mini-sized cards, print them at 100% scale. When printing maxi-sized cards, print them at 50% scale (or else they'll come out way too big: four times the intended surface area!).
Example: click/tap the card on the right to toggle between mini and maxi modes.
One interesting side-effect of printing to PDF (at least on modern Linux systems) is that the cards are exported in vector format, as opposed to raster format. What does that mean? It means great! The resulting PDF can be dragged/dropped into the Inkscape SVG editor to convert them (one page at a time) to SVG, where they can be further re-scaled or manipulated.
There is one caveat when doing so: Inkscape's import uses, by default, an internal conversion which requires (for proper display of the results) that the proper fonts be installed on your system. Since you likely don't have those installed everywhere, the preferred approach is to use Inkscape's "poppler" conversion option: when dragging/dropping a PDF into Inkscape, "poppler" is the top-most option, but is not selected by default. Select it. That will cause the fontified text to be converted to SVG "paths", which means that they're no longer editable as text but they'll be 100% faithful renditions of what appears in the PDF.
That same approach can almost certainly be used with other SVG editors (like the Adobe product line), but i've got no experience with those. If you're using a high-dollar graphics editor, i'm going to assume that you know what needs to be done to properly import these PDFs into it.