Homebrew
Spellcasting. Frostee's spellcasting ability is Intelligence (spell save DC 16, +8 to hit with spell attacks). Frostee is an 8th level spellcaster and can cast the following spells:
Arcane Restoration (1/day). During a short rest, Frostee regains the use of expended spells with a combined level of four or lower. Morellonomicon. Frostee can use his spellbook as a spellcasting focus for his spells. Sculpt Spells. When Frostee casts an evocation spell that affects other creatures that he can see, Frostee can choose a number of them equal to 1 + the spell's level. The chosen creatures automatically succeed on their saving throws against the spell, and they take no damage if they would normally take half damage on a successful save. Telekinetic. Frostee can cast mage hand without verbal or somatic components, and he can make the spectral hand invisible.
Staff. Melee Weapon Attack: +2 to hit, reach 5 ft., one target. Hit: 5 (1d6 + 2) bludgeoning damage, or 6 (1d8 + 2) bludgeoning damage if used with two hands. Chime of Opening. Frostee can strike the chime as an action, pointing it at an object within 120 feet of him that can be opened, such as a door, lid, or lock. The chime issues a clear tone, and one lock or latch on the object opens unless the sound can't reach the object. If no locks or latches remain, the object itself opens. The chime can be used ten times. After the tenth time, it cracks and becomes useless.
Telekinetic Shove. Frostee can try to telekinetically shove one creature he can see within 30 feet of him. The target must succeed on a DC 16 Strength saving throw or be moved 5 feet toward or away from Frostee. A creature can willingly fail this save. Summon Annie (1/Short or Long Rest). Frostee magically summons Annie (using the actions and statistics of a riding horse). Annie appears in an unoccupied space within 5 feet of Frostee, whom she obeys. She takes her turn immediately after Frostee. She lasts until she or Frostee dies, or until Frostee dismisses her as a bonus action.