In addition to sarrukh, monster manual gives an updated description of mind flayer race
+2 Strength, +4 Dexterity, +2 Constitution, +8 Intelligence,
+6 Wisdom, +6 Charisma.
—A mind flayer’s base land speed is 30 feet.
—Darkvision out to 60 feet.
—Racial Hit Dice: A mind flayer begins with eight levels of
aberration, which provide 8d8 Hit Dice, a base attack bonus of +6,
and base saving throw bonuses of Fort +2, Ref +2, and Will +6.
—Racial Skills: A mind flayer’s aberration levels give it skill
points equal to 11 × (2 + Int modifier). Its class skills are Bluff,
Concentration, Hide, Intimidate, Knowledge (any), Listen, Move
Silently, and Spot.
—Racial Feats: A mind flayer’s aberration levels give it three feats.
— +3 natural armor bonus.
—Natural Weapons: 4 tentacles (1d4).
—Special Attacks (see above): Mind blast, psionics, improved
grab, extract.
—Special Qualities (see above): Spell resistance equal to 25 +
class levels, telepathy 100 ft.
—Automatic Languages: Common, Undercommon. Bonus
Languages: Abyssal, Aquan, Draconic, Dwarven, Elven, Gnome,
Infernal, Terran.
—Favored Class: Wizard.
—Level adjustment +7
unless I'm wrong PRC has, for illithids, +8, instead of +7
