You learn the Find Familiar spell and can cast it as a ritual. The spell doesn’t count against your number of spells known and does not require material components for you. When you cast the spell, you can choose one of the normal forms for your familiar or one of the following special forms: imp, pseudodragon, quasit, or sprite. The familiar’s maximum health is increased by an amount equal to your warlock level and you add your proficiency bonus to its AC, saving throws and attack rolls. Your familiar’s attacks benefit from your Warlock’s Curse(Homebrew) feature and count as magical for the purposes of overcoming resistance and immunity to nonmagical weapons. If your familiar forces a creature to make a saving throw, it uses your spell save DC. Additionally, when you take the Attack action, you can forgo one of your own attacks to allow your familiar to make one attack of its own, or use any other one of its actions.
When you reach 10th level in this class, you can summon or banish your familiar as a bonus action instead of an action. In addition you can command your familiar to attack as a bonus action. Finally, you can cast Find Familiar as an action without using a spell slot and without any costly material components. When you’ve cast the spell this way, you can’t do so again until you finish a long rest.