The straight up regular non magical cat

One day you decided to give your soul to a cat. A straight up regular non magical cat. Maybe it's your beloved pet, maybe it's someone else's, or maybe it's a random stray who you somehow managed to give you soul to. Despite the fact it doesn't understand what a "patron" or a "pact" is, you somehow gain power, though it's just as likely something else giving you power for completely coincidental reasons, because it really doesn't make any damn sense. This is a joke subclass.

expanded spell list

Starting at 1st level, your cat somehow gives you the following spells added to the warlock spell list

1st: Sleep, Feather Fall

2nd: Misty Step, Mirror Image

3rd: Catnap, Nondetection

4th: Greater Invisibility, Freedom of movement

5th: Dominate Person, Passwall

The Zoomies

Starting at 6th level, you develop a moderately stronger bond with your cat. When you take the dash action, it lasts until the end of your next turn instead of ending as soon as your current turn ends. Additionally, the first spell you cast while under the effects of any movement speed increasing effect uses a bonus action instead of an action.

Claws of clawing

at level 10, when dealing damage with a spell, you may use your reaction to add slashing damage of the spell's damage dice to the damage.

No thoughts, head empty

At level 14, you gain a permanent effect which makes your thoughts and mental presence undetectable. Any spells or actions used on you that vary based on your intelligence score will consider your intelligence score as 0. You also gain resistance to psychic damage.