One or two zombies is an annoying fight, but a group or horde is something that can put everything else the party was planning on hold. The easiest way to do this is by modifying a swarm stat ...
Gherkin, horde, uhlan, kielbasa, schlub... The Internet is full of examples of words of (supposedly) Polish origin that have made it into the global English lexicon (here’s a full list). These are ...