Wizard: Necromancer

Original Source: Player's Handbook

Necromancy Savant

2nd-level Necromancer feature
Choose a 1st-level Necromancy spell from the Wizard spell list. Add this spell to your spellbook in addition to the spells you normally learn each level. Whenever you gain the ability to cast Wizard spells of a new level, you may choose another Necromancy spell from the Wizard Spell list of that level or lower and add it to your spellbook.

In addition, the gold and time you must spend to copy Necromancy spells into your spellbook is halved.

Grim Harvest

2nd-level Necromancer feature
As in the Player's Handbook with the following added:

Additionally, once per turn when an undead creature under your control kills a creature, it gains temporary hit points equal to the slain creature's CR or level (minimum 1). It doesn't gain this benefit for killing constructs or undead.

Undead Thralls

6th-level Necromancer feature
At 6th level, when you cast animate dead, create undead, or danse macabre, you can target one additional corpse or pile of bones, creating another undead creature, as appropriate.

Additionally, whenever you create an undead using a necromancy spell, it has additional benefits:

Inured to Undeath

10th-level Necromancer feature
Beginning at 10th level, you have resistance to necrotic damage, and your hit point maximum, Strength, Dexterity, and Constitution scores can't be reduced. You have spent so much time dealing with undead and the forces that animate them that you have become inured to some of their worst effects.

Command Undead

14th-level Necromancer feature
As in the Player's Handbook with the following added:

You may assert control over undead creatures commanded with this ability with animate dead or create undead, ending this ability on that creature, provided it meets all of the appropriate prerequisites.