The Marvel comics have a rather storied history with mythology. It isn't uncommon to come across a unique take on a deity that someone later finds out was largely made-up just to add some multi-national flavor to a storyline. This has mixed results, sometimes creating a god that fans love, and sometimes, coming off as othering (and even a bit racist at times).
But comic artists and writers have grown a lot, and many more recent takes on the Marvel pantheon have been created with much more consideration given to the cultures and peoples being represented by these gods. With the upcoming movie Thor: Love and Thunder promising gods galore, there are several potential additions to the MCU that would fit perfectly in the film.
Bast
Bast has been referenced already in the MCU and seen briefly on-screen in Black Panther. Originally based on the Egyptian goddess Bastet, a housecat goddess, Bast is a panther goddess worshipped in Wakanda. T'Challa and N'Jobu describe her as a spiritual and otherworldly guide who led the first Black Panther to his powers and leads the dead to the afterlife.
With some of the reveals in Moon Knight regarding the afterlife and gods, it would not be a far stretch to bring Bast more fully into the mix. And with the unfortunate passing of Chadwick Boseman, a very touching moment could be made of the Goddess guiding him on into the afterlife.
Kukulkan
Kukulkan is the winged wind serpent of Mayan mythology. He has appeared in the Marvel comics in the past as a snake-man 'god' during a storyline in which Inhuman imposters of the Mayan pantheon attempted to take over the world. The Hulk handily defeated them, but the Mayapan is begging for a better appearance.
Kukulkan is one of the most visually inspired deities around and would look incredible in the technicolor stylings that Taika Waititi's Thor films appear to favor. Additionally, as a God of Wind, there is ample room for Thor to find a good friend in the snake. Kukulkan would fit perfectly into the world expected in the film.
Atum
Also known as the "Demogorge" or the "God-Eater," Atum could make a surprising addition to the Love and Thunder pantheon. Atum began his life in the comics as the Egyptian god, Amon Ra, The Sun God, but would regularly become the Demogorge in order to consume demons and rebel gods alike. He often served as an afterlife guide for fallen Gods.
Because of his status as God-Eater, who provides a way to the afterlife for Gods who might not be able to die otherwise, he would fit into the film as an unexpected 3rd-act villain - or someone for Gorr the God-Butcher to face. Details of what to expect from the film are still scant, meaning there is room enough to put in almost any possibility - even one as massive as Atum.
Sl'gur't
Seeing alien Gods is almost a certainty with the purported plot of Thor: Love and Thunder. The trailer already features the corpse of Falligar, who is a massive beast who "wrestles black holes for fun." But there is almost an infinity of pantheons to choose from in the MCU, with just as much potential to just make one up.
But audiences have seen much of the Skrull shape-shifting aliens already, particularly in Captain Marvel. These aliens have a warrior goddess Sl'gur't, who has made frequent appearances in the comics alongside Kly'bn, her lover. Both could make very important appearances since we know the Skrull are working with Nick Fury.
Pele
Thanks to the massive success of Moana, and Taika Waititi's own Pacific Islander and Jewish heritage, it would make a lot of sense for Thor: Love and Thunder to introduce a Pacific Islander god. There are many mythological characters that could be introduced from the region, which contains many rich and varied cultures.
Pele is the Goddess of Volcanos and Lava, which would provide her with an easy theme for VFX artists to build around. She is also most commonly depicted as a young woman, which could lead to several great casting decisions - perhaps opening up the possibility for Moana herself, actress Auli'i Cravalho to join the MCU.
Nezha
One of the most popular and commonly seen figures from Chinese legend is Nezha, who is a protector god.
Nezha is commonly featured in many stories and video games today (but more than just topical, Nezha is also narratively similar to Thor). Both are 'golden sons' of sorts, who find joy in battle and strive to serve their parents. Audiences have yet to see Thor look back on his relationships with his mother and father - Nezha could be a catalyst.
Amatsu-Mikaboshi
One of the more Marvel-connected gods, Amatsu-Mikuboshi has shown up in several Marvel comic storylines as an enemy of Thor and Hercules (who many fans expect to see appear alongside Zeus). Amatsu-Mikuboshi has a mixed past, with a few storylines offering him up for redemption, but often remains evil.
In the comics, this god represents the primordial darkness that came before Earth existed, but, in the original mythology, he was merely a trickster who refused to join with the other heavenly gods - which includes other major deities, such as the Sun goddess Amaterasu and Susanoo - another God of Storms and Thunder.
Gaea
In the comics, Gaea is the birth-mother of Thor, as well as the mother of many other Gods. She is one of the first beings, in general, to exist on Earth, and the longest-living as well. In fact, over the course of her life in the comics, she has taken the role of dozens of other Mother Goddesses, including the Maori goddess, Papa.
Gaea's appearance could be a very complicated one, emotionally, for Thor. However, after so much death in his life, it could be interesting to see him in relation to a Goddess of Life. What's more, as the Mother Goddess she would make a major target for the purported villain of Gorr the God-Butcher, since she is one of the few able to birth new gods.
Chthon
As a counterpart to Gaea, Cthon is another of the primordial gods available from the comics universe. Chthon is one of the evilest of deities and is often the creator of the Darkhold. The Darkhold is the Necronomicon-esque book of evil magic that has been seen in Wandavision and Doctor Strange in the Multiverse of Madness.
What comic book fans will know is that Chthon is often there to utilize, and sometimes power, black magic. It is his dark and evil tendencies that get him eventually trapped in a different dimension altogether (which would provide an interesting way of working the multiverse into an otherwise straightforward-seeming film).
Leir/Raijin
One of the most meaningful and interesting uses of deities in Thor: Love and Thunder could be bringing in other Gods of Thunder and Lightning-like Thor - Gods like Leir of Celtic legends, Chaac of Mayan, or Raijin of Japan. While fans only have a few films and shows so far, there is a theme rising in this phase of the MCU.
So far, films like Spiderman: No Way Home and Doctor Strange: Multiverse of Madness have heavily featured multiple versions of MCU characters. With Thor's discussion of his place in the universe and the introduction of Lady Thor in the trailers, Love and Thunder is posed to examine Thor via other 'versions of himself' throughout other mythologies, much like these other films and shows have done.