Nope, and in those latest guesses, I only like Shellder (but, you know, only in as much as I don't not like it - plus the Ice thing helps).
That's not a clue, by the way. It's not an Ice pokémon I'm looking for.
And that's not a play on words either ("not a nice pokémon"...).
"Undercover agent", "tree resin". Go for the synonyms, and the rest should follow.