Hmmm, let's just go with SR 14.
I'll update the
Working Draft with SR 14, although I suspect Shade might change it to CR +6 later on...
Ranks of Hide 13, Move Silently 5, Listen 8?
Its Dex and Huge size gives it a hefty Hide penalty.
We could give it mostly stealthy-related feats to compensate - e.g. Stealthy, Skill Focus (Hide), Skill Focus (Move Silently) - or add a racial bonus to Hide and/or Move Silently. I'd favor something like a racial bonus to Hide checks when it subterranean environments, since it's "easy to spot in the open".
So, how about this:
Skill Ranks: Hide 9, Move Silently 9, Listen 8
Skills: Climb +11, Hide +2*, Move Silently +10, Listen +8
Feats: Improved Initiative, Reckless Offense
[?], Stealthy, Weapon Focus (slam)
Skill bonuses: A dense pudding has a +4 racial bonus on Hide and Move Silently checks. A dense pudding has a +8 racial bonus on Climb checks and can always choose to take 10 on a Climb check, even if rushed or threatened.
*A dense pudding has a +8 circumstance bonus to Hide checks in underground caves.
[A Gray Pudding is even better at ambushing, so methinks we'd better give the Gray a +12 circumstance bonus and SF (Move Silently)]