Small grows to HUGE Constructs..ideas?

[megamania]

For a game I will be running at a convention, I am using a Clockworker Horror. Only it is HUGE, not small. The one I had in mind was the Electrum version. What CR am I looking at? I was hoping for CR of 12 but I am beginning to believe a HUGE Clockwork Horror may exceed a 12CR. Thoughts or ideas from those that tinker with sizes/CRs alot? I would appreciate it.

 

[the Jester]

oops... double post.

 

[the Jester]

I had a long arc in my campaign that ended the 2e era with a party of very high-level characters (including Lester) battling a major infestation of clockwork horrors, an informational entity that controlled the horrors and a Drow lich with a magical metal arm.

One of the big battles involved a humungous horror that served to transport an army of other horrors inside it. It controlled and was controlled by a captured dwarf who was 'wired in' to it (he provided it with indepedent reasoning and creative response capability and was forced to do Master Control's bidding). The pcs had to save him (Belmondo the Enhanced, another pc who had been thought dead for decades), and destroying the giant horror would have killed him as well.

 

[megamania]

Wish mine was more original. I'm doing the comicbook heroes, the Avengers, but in a DnD Fantasy setting for a convention here in Vermont.

Characters are 15-23 levels (Black Widow to Thor in levels).
The Awakened Adamantium Golem known only as Warlord Ultron is sick of the meat things and trys to take them out using a giant metalliac cockroach with blasters. (I'm using Hero Clix for figures and a metalliac beetle toy from a Spider-man toy of the 90's).

I guess The CR really isn't that important under those conditions but I just wanted to know. Guess I'll bounce the Guess-o-meter (Dragon #276) on it. I want it to draw heroes into the conflict, not kill them.

Bad DM- Bad!