uglifyjs: command not found
My problem was that I installed uglifyjs, and not uglify-js. uglifyjs does not include the binary. Just leaving this here if someone else is stuck the same way.
sudo npm install -g uglify-js
Using @micans comment above, and this answer, I was able to get uglify working by adding export PATH=$PATH:/usr/local/share/npm/bin/ to my .bash_profile. Thanks all!