Planar Ally(Player's Handbook v.3.5, p. 261)
Conjuration (Calling) [see text for lesser planar ally]
Level: Cleric 6, Hathran 6, Summoner 6,
Effect: One or two called elementals or outsiders, totaling no more than 12 HD, which cannot be more than 30 ft. apart when they appear
This spell functions like lesser planar ally, except you may call a single creature of 12 HD or less, or two creatures of the same kind whose Hit Dice total no more than 12. The creatures agree to help you and request your return payment together.
XP Cost: 250 XP.