Extremely High Op Master Transmogrifist. Favored Shapes?

[MaxiDuRaritry]

Pretend, for a moment, that you're a level 21 wizard/master transmogrifist, from CArc. You're dealing with things on a regular basis that should be WELL outside of your weight class due to a DM known for tossing seriously heavy hitters at his players, and are often expected to deal with things on your own -- except for allies gained through feats and such.

What are the best forms you can think of for pulling some serious weight over the course of an epic campaign? Consider that Reserves of Strength is being used to break the HD cap for polymorph due to it being an epic game, to keep master transmogrifist relevant. Type is irrelevant, for now.

I thought about using the following: Dire Tiger, Greater Doppelganger, (eventually) Hagunemnon, Hydra [12 headed], Megaraptor Dinosaur, Mimic, and (eventually) Prismatic Dragon [Great Wyrm].

I figured each of them has a few things going for them (even if it's just because dinosaurs are cool). But does anyone have other ideas for good base forms for favored shapes? And why?

[ATHATH]

You're a high-op character with epic spellcasting available to you. Nothing should be above your weight class.

Since nothing is above your weight class, by "WELL outside of your weight class", you must mean that you're dealing with things well below your weight class. I recommend giving out quests and cryptic advice.

[MaxiDuRaritry]

You're a high-op character with epic spellcasting available to you. Nothing should be above your weight class.Epic Spellcasting is available but...discouraged, except where needed by the plot. In this case it's mostly plot-centric rituals and such, rather than "I cast an epic spell and win."

[flappeercraft]

Sarrukh is an obvious one, so are Protean and Chronotyrin. All of those are pure fold for MT

[ATHATH]

Epic Spellcasting is available but...discouraged, except where needed by the plot. In this case it's mostly plot-centric rituals and such, rather than "I cast an epic spell and win."
Oh. Well, in that case, since you have 9th level spells, which is the next-best thing to having epic spellcasting, nothing is above your weight class (still).

Also, I think I ninja-edited you.

[Goaty14]

I don't know how useful it is, but I'll just throw in The Master of Many Forms Bible (http://www.giantitp.com/forums/showthread.php?472737-Updated-Master-of-Many-Forms-Bible-official-wild-shape-rules-(recovered)) basically gives a list of forms with (ab)usable Ex abilities.

[Anthrowhale]

An Archivist 1/Transmuter 3/Mystic Theurge 6/Master Transmogrifist 10 taking Practiced Spellcaster[Archivist], Practiced Spellcaster[Wizard], and Theurgic Specialist has a caster level of:
Archivist 11
Wizard 19
Transmutation spells: 30
And the next 4 levels of Mystic Theurge push the caster level of Transmutation spells up to 38.

If you are willing to drop Master Transmogrifist, you can reach Transmutation caster level 51 via Illumian[Krau] Beguiler 1/Transmuter 4/Ultimate Magus 10/Archmage 5 providing full access to Protean at ECL 20.

[Eldariel]

You could also just do oldfashioned Consumptive Field persisting and stacking to the same effect getting you to base CL x 2. To get to 50, all you need is like Beads of Karma and Orange Prism and bags of rats or whatever to sacrifice. Epic forms are certainly interesting. Aleax's immunities too perhaps.

[Jack_Simth]

Well, you'll want to use PaO or Shapechange so that Construct forms are on the table, but....

Ocean Giant. It has immunity to Bludgeoning. Combine with the Xodar's Invulnerability to be explicitly immune to everything except bludgeoning. Kill things slowly with your fists.