Geckos are cool because they use the very weak Van Der Waals force to cling to stuff, which is incredibly awesome.
Also, because Anoles have similar feet, but they evolved them separately, which is also super cool. And Anoles are great because I just read a book about evolution by a guy who studied how, on a bunch of different islands in the Caribbean, the Anoles diverged into the same 4 or so roles - evolving along such similar paths that you’d be inclined to think that the tree anole on island 1 is related to the tree anole from island 2, but in fact all 4 types of anoles on each island evolved from a common ancestor that first arrived at the island and then diverged into one of 4 roles in extremely similar ways.
Improbable Destinies, a fantastic book about whether evolution is predictable, evolving into specific niches again and again - or unpredictable, heading down totally different paths based on tiny and completely random one in a trillion mutations.
(Spoiler: the book’s answer is, a bit of both at different scales)