Feebas and Milotic arrive in Pokémon Legends: Z-A through the Mega Dimension DLC, and their evolution works differently from the old Beauty-based methods. In this game there is only one way to evolve Feebas: a trade evolution that uses a Prism Scale.
Feebas evolution method in Pokémon Legends: Z-A
In Pokémon Legends: Z-A, Feebas evolves into Milotic only when it is traded while holding a Prism Scale. Leveling up, friendship, and Beauty do not matter here; the evolution will not trigger without the item-and-trade combination.
Step 1: Put Feebas in your party and open your bag. Select a Prism Scale and choose the option to give it to a Pokémon, then assign it to Feebas so it is holding the item.

Step 2: Start a trade (either local or online) from the in-game trading menu and offer the Feebas that is holding the Prism Scale.

Step 3: Once the trade completes, that Feebas will automatically evolve into Milotic during the trade animation. The same is true for the other player if their Feebas is also holding a Prism Scale.

There is also a commonly used global trade code dedicated to this evolution: 0048 0048, matching Feebas’s Hyperspace Pokédex number. When both players use this code and send a Feebas that is already holding a Prism Scale, each of them finishes the trade with a newly evolved Milotic.
How to get a Prism Scale in Pokémon Legends: Z-A
Feebas cannot evolve without a Prism Scale, and the DLC makes Prism Scales fairly limited early on. There are two reliable ways to obtain them.
Prism Scale from Side Mission 160: Feebas’s New Friends
The first guaranteed Prism Scale comes from a late-DLC side mission.
Step 1: Progress through the Mega Dimension DLC until Hyperspace Lumiose Survey No. 3 is complete. This survey involves the Mega Tatsugiri encounter.

Step 2: After finishing that survey, go to the canal area just west of Wild Zone 2 near Cafe Woof (sometimes called Vert Plaza). Look for the Soucian NPC standing by a pond with a Houndour.
Step 3: Talk to her to start Side Mission 160: “Feebas’s New Friends”. She will ask you to bring her a Feebas.

Step 4: Give her one of your Feebas to complete the mission. She keeps the Feebas you hand over, and in return, she gives you prize money and a single Prism Scale.
Prism Scales from Hyperspace Wild Zones (Golden and normal Poké Balls)
More Prism Scales can drop as loot in high-rank Hyperspace Wild Zones, which is important if you want multiple Milotic or you used your mission reward already.
Golden Poké Balls in 5-star Hyperspace Wild Zones
Step 1: Enter a 5-star Hyperspace Wild Zone and complete every objective in that zone.

Step 2: After the last objective is cleared, search the area for a floating Golden Poké Ball that appears on the map.
Step 3: Break the Golden Poké Ball. It always contains a large bundle of items, and it has a chance to include a Prism Scale.
Donuts can improve these odds. Donuts with the perk “Item Power: Special” increase the drop rate of special evolution items from floating Poké Balls, including Prism Scales. If the donut also has a perk like “Big Haul,” the number of drops per run increases, which indirectly gives you more chances at rare items.
Normal floating Poké Balls in 5-star Hyperspace Wild Zones
Players also see Prism Scales from normal floating Poké Balls in 5-star Hyperspace Wild Zones, especially while running a donut with “Item Power: Special.” These drops are rarer than Golden Poké Ball rewards but allow you to collect extra Prism Scales during normal farming runs.
Feebas location in Pokémon Legends: Z-A Mega Dimension
Feebas only appears in Hyperspace content tied to the Mega Dimension DLC, and it is restricted to specific kinds of distortions.
Step 1: Unlock at least 2-star Hyperspace Wild Zone distortions as you progress the DLC.

Step 2: From Lumiose City, check the current Hyperspace Wild Zones on the map. You are looking for distortions that:
- Are rated 2 stars or higher.
- Have the Water-type icon under the distortion.
Step 3: Highlight each eligible Water-type zone and inspect the Pokémon portraits shown for that distortion. If you have never seen Feebas in this save file, its portrait shows up as a greyed-out silhouette on the left side of the lineup. Otherwise, you will see its normal icon.

Step 4: If no current Water-type 2-star zones contain Feebas, rest on a nearby bench in Lumiose City to change the time of day. This rerolls the active Hyperspace Wild Zones. Check the map again and repeat the process until you see Feebas listed.
Step 5: Enter the distortion that lists Feebas and search the water areas inside. Feebas spawns at a relatively low level and does not put up much of a fight, so capturing it is straightforward once you are in the right instance.

Feebas is a bit rarer than many other DLC additions, but once you are cycling 2-star Water-type zones regularly, you should encounter it without an extreme grind.
Best practices for evolving rare Feebas (shiny and Alpha)
Because the evolution requires trading, many players use touch trades to evolve shiny or Alpha Feebas safely.
Step 1: Before trading, confirm with your trading partner that you are performing a touch trade and that both of you intend to trade back the evolved Pokémon.
Step 2: Make sure your rare Feebas is holding a Prism Scale and that your partner is ready with their own Feebas or another Pokémon you agreed on.
Step 3: Complete the first trade so your Feebas evolves into Milotic on their side.
Step 4: Immediately set up a second trade and have your partner send back the newly evolved Milotic. Do the same for their Feebas or Porygon line evolutions if you are returning a favor.
Communities often standardize on link codes (such as 0048 0048 for Feebas) to make it easier to find trade partners who understand what you are trying to do.
Once you have at least one Prism Scale and a Feebas from the right Hyperspace Wild Zones, evolving it into Milotic comes down to a single well-planned trade. The main friction points are timing Side Mission 160 correctly and farming extra Prism Scales through 5-star Hyperspace Wild Zones with the right donut perks. After that, you can evolve as many Feebas as your Prism Scale supply allows.