The description of Otherworldly Steed's Slam attack says:
Otherworldly Slam. Melee Attack Roll: Bonus equals your spell attack modifier, reach 5 ft. Hit: 1d8 + the spell's level of Radiant (Celestial), Psychic (Fey), or Necrotic (Fiend) damage.
Otherworldly Slam. Melee Attack Roll: Bonus equals your spell attack modifier, reach 5 ft. Hit: 1d8 + the spell's level of Radiant (Celestial), Psychic (Fey), or Necrotic (Fiend) damage.
But the Steed has a Strength attribute of 18 for a Strength modifier of +4. Does it also add its Strength modifier to the attack and damage rolls of its Slam?