Relentless Endurance. When reduced to 0 hit points, Grum'shar drops to 1 hit point instead. He can only do this once per long rest.
Spellcasting. Grum'shar is a 1st-level spellcaster. His spellcasting ability is Intelligence. He has the following wizard spells prepared:
Cantrips (at will): fire bolt, mending, prestidigitation
1st level (2 slots): burning hands, disguise self, shield
Dagger. Melee Weapon Attack: +2 to hit, reach 5 ft., one target. Hit:2 (1d4) piercing damage. Or Ranged Weapon Attack: +2 to hit, range 20/60 ft., one target. Hit:2 (1d4) piercing damage.
Apprentice wizards are novice arcane spellcasters who serve more experienced wizards or attend school. They perform menial work, such as cooking and cleaning, in exchange for education in the ways of magic.