So far the best OTP (design) book that I’ve encountered is still Designing for Scalability with Erlang/OTP-Implement Robust, Fault-Tolerant Systems. The ebook is available DRM-free from Google Play Books and ebooks.com. The free sample on Google Play Books covers everything up to most of Chapter 4.
The Chapter 2 Erlang primer should be enough to get an Elixir developer going to understand the Erlang code - which isn’t that difficult to port to Elixir.
Functional Web Development with Elixir, OTP, and Phoenix would be a great follow up as a demonstration in the pure Elixir space with Phoenix (don’t forget the forum discount).
If you are still looking for a more introductory Elixir text Elixir In Action - 2e is a good choice for an experienced programmer with its more “Erlang-oriented” approach - and it dabbles a little bit with OTP (for a few more hours half off).
Fred Hébert:
