1/2 a 100!- T1B50

Here's a riddle from one of the Harry Potter books. Everyone should know it, since most people read this novel:

First think of the person who lives in disguise
Who deals in 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 finally give me the sound often heard
During the search of a hard to find word.
Now string them together, and answer me this,
Which creature would you be unwilling to kiss.

I dug up this riddle from the book last night. It's unusual and really clever.

BTW, if you haven't guessed out the answer yet, it's "spider".
string "spy" and "uh" together, and say it fast.