What creature type are the Pact of the Chain warlock's additional familiar options?

Question

The find familiar spell states that

the familiar [...] is a celestial, fey, or fiend (your choice) instead of a beast.

To my understanding, all familiars conjured by find familiar are actually just spirits in the shape of the chosen creature (rather than a true example of the creature itself).

But since the spell specifies "instead of a beast", do the Pact of the Chain warlock's additional familiar options (imp, quasit, pseudodragon, and sprite - none of which have the beast type) not change creature type to match the spirit that took their form?

Answer 1

The creature types are Fey, Celestial and Fiend

For a simple summoning, Sprites are fey, while Quasits and Imps are fiends. That leaves the question open for the pseudodragon. It can be a fey, celestial, or fiend in the form of a pseudodragon (as the spell description states). Nothing in the pact description contradicts that.

When you cast the spell, you can choose one of the normal forms for your familiar, or one of the following special forms.

Without getting complicated, three out of four special forms already coincide with fey, fiend, or celestial. The pseudodragon (form) can be any of the three, since the spell's features otherwise hold in this case. (PHB p. 107).

The form and the spirit don't have to match if the Warlock wants to mix it up. That could be fun.

Mix and match? Sure, nothing prohibits it

You gain the service of a familiar, a spirit that takes an animal form you choose

The familiar is a spirit that takes a form. That's as specific as the spell gets, beyond it having to be a beast (for a regular casting of find familiar - beasts from the list), or the additional choice of special creatures if it's a summoning from a Warlock with Pack of the Chain. (The Warlock could summon a weasel form if they wanted to; they don't have to summon a special).

If the Warlock so desires, they can summoning a fiend spirit in the form of a sprite or a celestial spirit in the form of an imp. All that changes is the form; that's a special feature of the Chain Pact. Whether or not that makes sense is up to the Warlock in question.

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Answer 2

The form is just a form.

You get to pick a form and a type for your familiar, independently. The form isn't tied to its type. You're certainly welcome to play into the archetype the form suggests, but it's not actually necessary.

Just because the imp in the book is a fiend doesn't mean your imp-familiar has to be. It doesn't even have to be an imp per se; "imp" is the mechanical description of this creature, but you could certainly describe it in some completely different way -- an imp belonging to a star-pact warlock might look like a tiny shoggoth; a fae imp might be a tiny, extremely hairy man that can turn into various animals; you might choose the Celestial patron and describe your 'imp' as a very small coatl. It's your choice.

Answer 3

You choose

The description for the extended choice is:

When you cast the spell, you can choose one of the normal forms for your familiar or one of the following special forms

You are choosing what form the "celestial, fey, or fiend (your choice)" that you are summoning with the spell is taking.

It is just expanding the list of possible forms, not specifically summoning those things directly instead.