That is the interlinear as provided by the New American Standard version.
Here's the interlinear (from Bible Hub).
http://biblehub.com/interlinear/mark/16-18.htm
Apparently some of the Greek texts have it in and some leave it out..
In any event I can assure you I will not go around trying to pick up snakes "in my hands" unless, as I said before, it is absolutely required..... LOL.