Wow!, that was a struggle, (although I seem to remember saying something similar only recently, so I hope it isn't the satart of a worrying trend......
20d Hunter ahead snaring S American banker (5) - ORION (Hunter)
Initially I thought this was 'Ahead' = ON + 'S American banker' = RIO, and just assumed the S A 'Banker' = 'River, but search as I may i can't find River Rio, so I've gone drastically wrong somewhere.