If anyone is wondering why it’s rejected by Esperantists, “crocodiling” (krokodili) basically just means speaking a language other than Esperanto in a setting where you’re only supposed to speak Esperanto. So that’s why it’s looked down upon. Esperanto events might even have signs posted warning people “ne krokodilu” — “don’t crocodile!” — and the above sign is a wordless version of such a sign.

The concept of “crocodiling” has been adapted into the communities of other constructed languages, Toki Pona loaned krokodili as kokosila.