The riddle

First think of the person who lives in disguise,
Who deals secrets and tells naught but lies.
Next, tell me what's always the last thing to mend,
The middle of the middle and the end of the end?
And finnaly give me the sound often heard
During the search for a hard-to-find word.
Now string them together, and answer me this,
Which creature would you be unwilling to kiss?