Innate Magical Ability
From AmtWiki
A term describing abilities of certain Monsters.
Description from the Dor Un Avathar
Unless listed as magical, Innate Abilities are non-magical in nature. Innate Magical Abilities are cancelled or Dispel by Anti-Magic areas. Targets bearing Protection from Magic and those who are immune to magic are likewise unaffected by these abilities.
Player Notes
Virtually any Monster ability that emulates an existing magical spell, along with many entirely new abilities, fall into this category. An exhaustive listing of these abilities would be of little use, as many abilities are magical for some monsters and non-magical for others. Consult the monster description in question when uncertain.