I believe what you are seeing is actually exactly as it should (if I have read this correctly) ..
the console.log() command is putputting text to the console, and as expected, prints the role of your creep...
the undefined is coming from the actual console.log() function call, ie if you put 1 into your console, you'll see 1 printed, if you put 1+1, you'll see 2 printed. its printing the result of the expression .. in your case console.log is returning undefined, as any function in javascript that does not explicitly return a value, will always return undefined (equiv to void in other languages)