D&Dtools1

You conjure a Large, quasi-real, horselike creature.
The steed can be ridden only by you or by the one person for whom you specifically created the mount.
A phantom steed has a black head and body, gray mane and tail, and smoke-colored, insubstantial hooves that make no sound.
It has what seems to be a saddle, bit, and bridle.
It does not fight, but animals shun it and refuse to attack it.
The mount has an AC of 18 (-1 size, +4 natural armor, +5 Dex) and 7 hit points +1 hit point per caster level.
If it loses all its hit points, the phantom steed disappears.
A phantom steed has a speed of 20 feet per caster level, to a maximum of 240 feet.
It can bear its rider's weight plus up to 10 pounds per caster level.
These mounts gain certain powers according to caster level.
A mount's abilities include those of mounts of lower caster levels.
Thus, a mount created by a 12th-level caster has the 8th, 10th, and 12th caster level abilities.
8th Level: The mount can ride over sandy, muddy, or even swampy ground without difficulty or decrease in speed.
10th Level: The mount can use water walk at will (as the spell, no action required to activate this ability).
12th Level: The mount can use air walk at will (as the spell, no action required to activate this ability) for up to 1 round at a time, after which it falls to the ground.
14th Level: The mount can fly at its speed (average maneuverability).

Special: When casting phantom steed as a Spider Domain spell, the steed has a vermin shape.