Pat: I haven’t seen the Zebra in awhile.
Me: He’s staying up near the top because the koi are down at the bottom. There he is. *points to the very top line of the water.*
Pat: Never mind that goldfish are vegetarians and insecticidal, they’ll eat worms.
Me: But the Zebra doesn’t know that.
Pat: Heh, let’s not tell him.

So far they angry zebra is staying away from the koi who have schooled. So is the Molly, sadly. I think she would get along fine with her koi friends. Though they are 3 times her size (in length, 5 times in girth).