Warlock - alternative patrons?

[Brookshw]

Just starting on 5e and am disappointed that Warlocks can't get Slaad or upper planars for their patrons. Are there any such options outside of core? If so, which books?

[Cikomyr]

Edit: Nothing core or rule based. My post below is purely fluff.

Web Gm had an interesting discussion about the underlying mechanics and theme of a Celestial Warlock Patron. Warlock's relationship with their patron is, after all, one of business. An exchange of power for services, that isn't meant to be about one 's devotion.

Therefore, a proposed idea was that a spawn of the low-planes (tiefling) who wants to either gets revenge or wipe his forebares by seeking the powers of Above. However, his fundamental nature limits his understanding of the Celestials' patronage of mortals through a life of virtue.

In a classic case of "evil doesn't understand good", the only type of relationship the Tiefling would understand is one of bartering. So maybe the Celestial would accept to lend his power, in exchange of... How about you have to selflessly help one person every day? I want you to go and anonymously cure a plague over there. Etc..

Slaads warlocks would be harder to achieve. How can you establish a deal with beings of pure chaos and expect them to back their words up? I suppose it could perhaps be a Wild Magic version of Warlocks.

Off course, why not go non-External Planes? You can always have an Archmage Patron, I suppose. Very powerful mortals.

A less sci fi magitek version of Ghost in the Machine could be having a Magical Intelligent Artifact. Think of being a Warlock with the One Ring as your patron?

[Millstone85]

The Celestial is in Xanathar's Guide to Everything.

[Particle_Man]

I refluffed a goo warlock as having primus the modron ruler as a patron. He got a clockwork owl familiar like the one in the original movie Clash of the Titans.

[R.Shackleford]

You're going to have to use a lot of homebrew/fluff if you want Warlock patron support.

I changed the fey to be the patron "Ufiaw", when I was describing my patron to my allies I was basically describing the typical tsundere woman from anime/manga. Took then a while to realize I was a Warlock with a waifu.

Looking back, I should have used the GOO for that one, but fey worked well.