here is and idea for a skeletal war elephant

WS3 BS0 S8 T6 Aspecial W10 I1 Ld10 armour 4 ward5

trample- if a war elephant is within charge range it may trample (2 d6 S8)
grap with trunk and...-pick one enemy model in base contact with the elephant then consult the table here 1-2 d6 S8 3-4 throw (same as giant) 5-6 Automaticly slain (ward may be taken)
Undead- same as TK's

I like the concept of it. But the rules should be changed abit, like the strength, wounds, and leardership of it would have to go down (sadly). Also the automatically slain would have to go down to us1 of 2 models, or else it would be a cagillian points (roughly 650 I think).

If you wanted something within realison of the game I think the stats would go like this:

Points 475, Takes up 1 rare and 1 specail

M:6 or 7 WS:2 B:0 S:6(7) T:6 W:7 A:Specail I:1 LD: 6 AS:5+ WSV:5+

Elephants Special Attacks:
1 Thunderous trumpet (wins combat by 2)
2-3 The elphants swings its trunk at the opposing unit and deals D6 strength 6 hit
4-5 Throw (same as gaint)
6 Massive Stomp (uses small blast template that touching from anywear from the elephants front at Str. 4, Killing blow. People are struck if they fail and I test.)

Ward Save:
Becuase of the huge amount of magic needed to control the elephant it is granted a 5+ ward save from the magical enegy surounding it.

Howda:
For an extra 60 points the elephant can transport a unit of 10-15 skeletons (also include the points for the skeletons). If armed with bows they can shoot from the elephants back.

If the Elephant is killed everyone in the howda takes a single strength 5 hit due to the fall down to the ground. Also if the elephant is struck by a str. 7 or more hit in the shooting or magic phase, roll a dice if a 6 is rolled the howda is hit, and is destoryed. The unit takes the falling test and then forms a unit beside the elephant.

Impaling Charge:
The elephant does D6 strength 7 hits when it charges into combat.

Summoning:
Due to it's shear size it is extremely hard to repair with the summoning incantations so only gets one wound restored with each succesful summoning.

Terror

Undead Construction

(Tomb King) Undead


Hope these rules would be what you were thinking along Jaba, I really due like this idea. Would make a great conversion for a seige tower B) .

Or why not make it an upgrade special mount for a tomb king?
Only one per army, takes up a rare slot, can join with chariot units...