"I always keep a supply of stimulant handy in case I see a snake, which I also keep handy"

This quote by W. C. Fields is an amusing method of revealing his readiness for any scenario. He is suggesting that he is always gotten ready for any potential danger, such as a snake, by having a stimulant on hand. The stimulant could be anything from a cup of coffee to a shot of bourbon, depending upon the scenario. By having a stimulant convenient, he is implying that he is prepared to do something about it if he sees a snake. He is likewise indicating that he keeps a snake convenient, which could imply that he has a pet snake or that he is prepared to encounter a snake in his environment. This quote is a funny method of revealing his readiness and his determination to do something about it if necessary.