Codecademy should add Elixir as a new language to their course options, it fits in well with the others as it is general purpose with some cool functionalities. It has a framework as well — Pheonix — that is used for web development and would blend in on the site very well.
For those not familiar with the language, it is a function oriented language as opposed to OOP, making it a bit different. If you’re familiar with Erlang, an easy way to think of it would be an updated Erlang.