Recruiting the Queens

There be spoilers here involving the appearance some characters and the inclusion of some locations.

Queens are the peak of monster races that most monsters aspire to one day be. As of Part 2 of Paradox, Queens are some of the strongest companions you can recruit and most of the have access to the exclusive Queen Advanced Races as the race change items are not in the game yet.

Demon Cow Queen
She aimed to be Queen Beast, but a young hero foiled her plans. Despite no Advanced Queen Race for her as of yet, she's a very strong physical fighter with minimal set up. To recruit her complete the Sukiyaki Party sidequest and show her the Horn of Friendship.
 * 1) Prove yourself to Grand Noah Queen in the main quest.
 * 2) Agree to help Cerberus.
 * 3) Talk to the red haired man sitting at the bar in the Grand Noah Bar.
 * 4) Talk to the Minotauros in the Blacksmith.
 * 5) Head west through the tunnel. Clear the Minotaur Maze and defeat the Demon Cow Queen.
 * 6) Go back to the tunnel. Give the Minotauros there 10 Sukiyaki for the Horn of Friendship.
 * 7) * 2 Sukiyaki can be found in the Minotaur Maze in the pots next to the entrance. All the Minotaurs inside also drop them. Or Flavor Emperor's learn the cooking recipe at level 9. Or stolen as food from Youki.
 * 8) Show the Horn of Friendship to the Demon Cow Queen and she'll join you.

Alraune Priestess
She's not quite Queen Alraune yet, but she will be soon enough and she's needed to recruit the old Queen Alraune which is why she's included on this list. Additionally, you should also be able to recruit her if you decided to side with her immediately, but that stops you from recruiting Queen Bee, so this is the ideal option.
 * 1) Once you make it to Plansect Village and talk to her, tell her you're not taking sides just yet (Option 3).
 * 2) Go talk to Queen Bee on Red Mountain and tell her you've just come to talk (Option 3). Then tell her to meet with Alraune Priestess and you'll broker peace (Option 3).
 * 3) Return to Alraune Priestess and broker peace (Option 2).
 * 4) Win the next two fights and then go talk to Alraune Priestess to recruit her.

Queen Bee
The most underwhelming entry on this list. She has no Queen Race and a mediocre unique trait. But, she's needed for either Queen Ant or Spider Princess to become Queen Insect hence her inclusion on this list.

Exactly the same as Alraune Priestess. Once you've brokered peace and won the two following fights, go talk to Queen Bee on Red Mountain and she should join you.

Once again, she'll join if you decide to side with her initially but that locks you out from recruiting Alraune Priestess.

Queen Ant
Once you've resolved the problems at Succubus and Lady's village, return to Grangold King for your reward. Now, Queen Ant should be recruit-able. Simply give her the honey from the Four Perverts side quest and she'll join the party. She doesn't have access to the Queen Insect Race yet, but she can gain it later. See Spider Princess for more details.

Queen Harpy
First, you must complete the Harpy Disappearance quest if that wasn't obvious enough.

After you defeat Queen Alraune, talk to her, return to Grand Noah Queen and tell her the threat has been neutralized. Return to Queen Alraune and she should have the Seed of Yggdrasil ready. Give that to Queen Harpy and she'll join you.

Queen Elf
Simply show her two trophies from the coliseum in Grand Noah to recruit her.

You can get a bronze trophy from the basic challenges. A silver trophy from completing one of the race trophies. And a gold trophy from completing 10 waves of the survival challenge.

Queen Fairy
Show her the Hide and Seek trophy from finding Amira 21 times and she'll join you.

Queen Alraune
Queen Alraune won't join you until Alraune Priestess takes up the position of Queen.
 * 1) Bring Alraune Priestess to her and she'll give instructions on how she can become a Queen.
 * 2) Alraune Priestess adamantly refuses, but you're the party leader so you drag her to Gold Beach, North-East of Godaaru.
 * 3) Find the crystallized sunlight. Alraune Priestess tells you to smash it, but it doesn't matter which option you take. Alraune Priestess becomes the new Queen Alraune and the old Queen Alraune joins your party.

Queen Mermaid
El should join the party after you stop her mother. Afterwards, she'll have a quest on the Pocket Castle Bounty Board. The steps are as follows if you don't like links.
 * 1) Talk to her on the Pocket Castle Boat.
 * 2) Follow her to the top deck and talk to her again.
 * 3) Talk to Queen Alraune.
 * 4) Plants seeds at Natalia Beach. Several events will occur one after the other at the beach. Exhaust the events and the quest will complete.
 * 5) Then, bring El to her mother and she'll join your party.

Spider Princess
She'll be a Queen if she can find a supportive husband. Note that you'll need have to resolved the Plansect Village civil war and recruited Queen Ant on your current playthrough to recruit Spider Princess.
 * 1) After you've defeated her and talked to the Grangold King, return to her after defeating the other queens, and she'll inform you that she, unfortunately, can't follow through on her marriage promise as she is a candidate to become Queen Insect.
 * 2) Tell her you'll help and she'll take you to meet Queen Ant and Queen Bee, the other two candidates.
 * 3) Now, the next two choices don't matter for recruiting Spider Princess. They only determine who gets the Queen Insect race. The first choice doesn't even matter at all. The first option says you believe Spider Princess has turned over a new leaf. The second option says you don't. The second choice just determines who gets the Queen Insect race.
 * 4) * If you support Spider Princess (Option 1), you fight Queen Ant and Queen Bee. Spider Princess will join immediately afterward, and gain access to the Queen Insect race.
 * 5) * If you choose to support Queen Ant and Queen Bee (Option 2), you'll fight Spider Princess again and Queen Ant will gain the Queen Insect race. You'll be kicked outside of Red Mountain, but if you return to Spider Princess afterwards, she says you can't believe her betrothed betrayed her, but then reveal she's super aroused by your sadistic behaviour and join your party anyways.

Queen Vampire
Max out Vanilla's shop in Part 2 or you won't be able to do this quest.
 * 1) Once Vanilla is a good enough shopkeeper, bring her to Queen Vampire who'll reveal she wants to start a pub in Sabasa.
 * 2) First, bring Vanilla to Salaan's house and talk to her there. Once things are set up there, talk to Queen Vampire and she'll send you for the best rugs available.
 * 3) Warp to the Navy Base and head west to Sheep Island. Talk to the Sheep in the doorway and she'll arrange for some rugs.
 * 4) Finally, Queen Vampire will ask for some of the finest alcohol. Go talk to Lazarus in the Pocket Castle Casino and you're done.
 * 5) * If you haven't recruited Lazarus yet, he can be found in the Goldport Pub after resolving the situation in Grangold.
 * 6) Talk to Queen Vampire and she'll join you.

Queens of the South and North Seas
As Queens of locations, rather than a race, they don't get any Queen Advance Races, but they're still decent enough recruits.

Go talk to Poseidoness in the North Sea Temple. She'll send you to Queen Mermaid. Go talk to her and she'll revive Kraken for you, who'll promptly join you. Then, bring Kraken to Poseidoness and she'll join you too.

Alma Elma, the current Queen Succubus.
Complete Part 2. Complete Promestein's second Ancient Temple Ruins trip request.

Former Queens
Defeat Cirque du Croix at the ruins south of the Bird God Shrine after completing Part 2 to recruit: Former Queen Scylla, Zenovia; Former Queen Lamia, Aria Lamia; Former Queen Harpy, Reflestia. They all have access to the responding Advanced Races. You must bring Chrome or you won't be able to fight them. You'll also get the Former Pirate Queen, Rosa, but she doesn't get any special jobs or races.

(Alice Route Only): Former Queen Succubus, Lilith and Lilim. I can't remember when they spawn, but go to the shrine east of Remina (Alt), near the tunnel exit and talk to the priest and they'll join up. You might have to beat Part 2 before you can recruit them.

Not a Queen per say, but Sphinx is the only one with has access to the Advanced Yoma Race, "Sphinx" so you might want to recruit her. She can be recruited while looking for the Yellow Orb. Simply defeat her, before or after getting the orb and talk to her to recruit her.