"just" crabapples? Some crabs are excellent eating, and even if you don't care for the fruit you still have a good tree to use as rootstock for a different, or several different, varieties. But I think it's not a crab, because the fruit are pretty good sized already (compared to what I'm seeing, anyway- we are having a late, cold spring and my apples are slow this year.)

It does look like a celosia seedling.

Yeah, I was thinking a species of nest parasite because of the disparity in size. It might have been trying to push its smaller nest mate out of the nest and got carried away with its pushing.

Nice that the trip was not for nothing. I am hoping Holland Park will get a new batch soon. They have a group of four or five different Lithops I really covet, but it is in a $60 combination bowl. Ugh. Potful like that is sold for under $10, but I cannot get it separately. Did you get the one top right at Harpers? I think I saw them labeled P. bracteosum?