Deskari
Deskari, also known as Lord of the Locust Host, is the Demon Prince of chasms, infestations and locusts. He appears as a massive locust with a human's torso and wings made from locust swarms.
One of the few Demon Princes in Pathfinder that isn't a direct port or even a direct reference to any older material, Deskari is the son of Pazuzu, botn from his first breath on the material plane, after which he begun Demon Princing fast and furious. More so than almost any other Demon Prince, Deskari has been extremely active in the Material Plane, so much so that his avatar actually manifested on Golarion before getting his ass handed to him by a wizard god wielding a sword and a shield. This understandably made the massive bug mildly livid, but he could do jack shit about it since the said wizard god still roamed the planet, promoting Humanity Fuck Yeah mentality. Eventually the wizard god disappears and Deskari gets to be the star of the show once more.
When the said wizard god disappeared, a giant opening opens in the northern parts of Avistan, Pathfinder's main setting, that starts spewing more demons than the planet has ever seen before. This was Deskari's cult lead by a half-succubus witch finalizing a ritual to open a direct and massive gateway to the Abyss. Named the Worldwound, Deskari and his ally Baphomet start expanding their influence on the material plane until they can physically manifest there. That would be very naughty of them due to the cosmic balance of things, but gods can't directly impact this so they just tell their paladins to Crusade the shit out of the the surrounding lands. This at best just delays the Worldwound expanding and feeds Deskari a fuckton of fresh souls to fuel his plans. This all leads him to be a direct rival of the resident paladin god of Deus Vult, Iomdedae, who also happens to be the pet paladin of the aforementioned wizard god. And on top of all this metaphysical bird flipping towards any Good gods in the setting, he also has a rivalry with a minor Demon Princess over who is the better insect god. Of course it's Deskari, but he can't just crash her domain and tear her spine out because she just happens to be the daughter of his father's unbelievably violent ex-girlfriend, Lamashtu.
He is a major antagonist in the Adventure Path Wrath of the Righteous and one of the three actual Demon Princes the PCs are somewhat expected to be able to fight were they to choose so, along with Baphomet and Nocticula. He appears only at the very end after the campaign has already been won as a super boss of sorts. Stats wise he is actually quite terrifying with high damage output, quadruple critical damage due to his choice of weapons, all sorts of high DC debuffs that active all the time and nearly impenetrable defenses by normal standards, he is actually quite disappointing when fought with max level characters with ten Mythic tiers. For all the hype he is given with even the book saying that the fight is supposed to be damn near impossible and that retreating is an entirely expected outcome he only comes off as a joke when a mythic fighter drops him in a turn with a single attack that deals well over three thousand points of damage and hits even on a nat 1.