A combination of the words 'Calgary' and 'Anonymous'. Used in 4chan to describe someone from the Canadian city of Calgary.
Anon: Anyone here from Calgary?!
Anon: same hear, holy shiiit
Anon: what the fuck is with all the calganons?
Anon: man, there sure are a lot of calganons on 4chan
Anon: are there any other cities in canada?
Anon: apparently not