Elemental Swarm

Elemental Swarm
(Player's Handbook v.3.5, p. 226)

Conjuration (Summoning) [see text]
Components: V, S,
Casting Time: 10 minutes
Range: Medium (100 ft. + 10 ft./level)
Effect: Two or more summoned creatures, no two of which can be more than 30 ft. apart
Duration: 10 min./level (D)
Saving Throw: None
Spell Resistance: No

This spell opens a portal to an Elemental Plane and summons elementals from it. A druid can choose the plane (Air, Earth, Fire, or Water); a cleric opens a portal to the plane matching his domain.

When the spell is complete, 2d4 Large elementals appear. Ten minutes later, 1d4 Huge elementals appear. Ten minutes after that, one greater elemental appears. Each elemental has maximum hit points per HD. Once these creatures appear, they serve you for the duration of the spell.

The elementals obey you explicitly and never attack you, even if someone else manages to gain control over them. You do not need to concentrate to maintain control over the elementals. You can dismiss them singly or in groups at any time.

When you use a summoning spell to summon an air, earth, fire, or water creature, it is a spell of that type. For example, elemental swarm is a fire spell when you cast it to summon fire elementals and a water spell when you use it to summon water elementals.
Special

When casting elemental swarm as an Air Domain spell, only Air elementals may be summoned.
When casting elemental swarm as an Earth or Dwarf Domain spell, only Earth elementals may be summoned.
When casting elemental swarm as a Fire Domain spell, only Fire elementals may be summoned.
When casting elemental swarm as a Water or Ocean Domain spell, only Water elementals may be summoned.