Familiars

Psychic bond
Familiars are more than a mere magical pet - they are an extension of mind, and a mirror of your soul. If your familiar is slain, make a DC 10 intelligence save or lose one hit die. If you have no remaining hit die, take 1d8 psychic damage instead.

An extra ability...
Depending on the category of your familiar (see below), it has or grants additional abilities.

Types of Familiar
Familiars now fall into 3 categories - A, B & C. Note that the statblocks below are modified versions of the strongest familiar in each category. If you feel your familiar's statblock should be unique, consult the DM.

* The spell is chosen on first acquiring the find familiar spell, and may be swapped out as per any other warlock spell.

Indivisible Wizards (wizards without familiars)
At wizard level 1, you may decide to make your character indivisible. Doing so means you are unable to acquire a familiar - you simply cannot perform the feat of psychic fragmentation required. 'Indivisibles' who are wise instead focus the mind's energies inward, gaining an additional 1st level spell slot. If you have ever had a familiar, by definition you cannot become an indivisible wizard.