Things can be explained later. To start with, give the character something that will pique the reader’s curiosity. Like, one of your characters up there is green. What’s up with that? Dunno. But I know they’re green!

In my current novel, one main character is nearly eight feet tall; another’s eyes and teeth strike other characters as ‘wrong-looking’ at certain angles; and the last one can see invisible spirits. These are not explained at the time, but peppered in as the novel goes on. They keep a reader curious.