A lot of players ask about the rarity of specific villagers, believing that some are more common than others. However, this is untrue and all villagers have an equal chance of showing up at your campsite or on a random island you can fly to. There are 393 animals in Animal Crossing New Horizons though, so the chance of seeing a particular villager is always relatively low. The best way to get Zell on your island is to purchase his amiibo card.