What does "extraplanar creature" mean in the Dismissal spell?

[Nareau]

Dismissal

Abjuration
Level: Brd 4, Clr 4, Sor/Wiz 5
Components: V, S, F/DF
Casting Time: 1 action
Range: Close (25 ft. + 5 ft./2 levels)
Target: One extraplanar creature
Duration: Instantaneous
Saving Throw: Will negates
Spell Resistance: Yes

This spell forces an extraplanar creature back to its proper plane. Add the creature’s HD to its saving throw and subtract the character's level as well. If the spell is successful, the creature is instantly whisked away, but there is a 20% chance of actually sending the subject to a plane other than its own.

Arcane Focus: Any item that is distasteful to the subject.

Outsider? Summoned creatures only? Gated creatures? Any creature not currently in its plane of birth?

 

[Trainz]

Any creature not native to the plane you are currently on.

Elementals, demons, aasimon... a LOT of the critters in thebook. My cleric always has a Holy Word spell memorised.

 

[Moon_Goddess]

Anything not from the plane you life on.

Elementals, most Outsiders (save for Planetouched), And if your playing in Greyhawk and Elminster comes for a visit, Dismissal his rear