The Frogs of Legend quest - which follows The Professor's Protege's red and yellow frogs and Gigantoad, Wyvern, Mrylwood Firefly and Griffon hunts - is essentially a needle in a haystack, asking you to find five rainbow frogs somewhere across the game's vast map.
The only clue? Their habitat is "water", and for a game with several lakes, rivers and coasts, that doesn't narrow it down by much.
Unless you want to scour every body of water in the game, here are the locations of the five Rainbow Frogs you've looking for. Even if you're searching the right general area, narrowing down the exact location can be difficult, so we've provided map screens too. Additionally, you'll hear a frog croak when you're in the general vicinity; use that as a general steer to know you're on the right path.
The Frogs of Legend Rainbow Frog locations
Once you have started up the quest from Sania - she's back at the Meldacio Hunter HQ, where you found her for the Myrlwood Firefly quest.
Rainbow Frog location - Alstor Slough
Go to Alstor Slough - it's in the east of Duscae - where there are two giant lakes to the east and west. On the northern tip of the eastern most lake (on the map it'll be south of the 's' and 't' in the area's text) and the frog will be on the lake's shore, under a bush.
Rainbow Frog location - Saxham Outpost
Locate where the 'Saxham Outpost' text is on the map - it's in west Duscae, to the west of Cauthess - and just above the 'x' is a small pond. Head there, and on the north east tip is a water tower. Run south along the western side, going between the fence and the pond, and by the rock further north is the frog.
Rainbow Frog location - Fort Vaullerey
Head to Fort Vaullerey (it's located in the south west of the game's map) and from there, take the short walk west to the river. Most of the bank is paved in concrete, but head just south of where it changes to natural beach. The frog will be by a rock just south of there.
Rainbow Frog location - between the Vesperpool and Rock of Ravatogh
This is just off the road between Rock of Ravatogh and the Vesperpool, specifically where the river heading south splits into two.
Park the car on the S-bend nearby (specifically just to the south so you can leap over the barrier) and head to the river side. You may encounter some Shieldshears on the way - at this point in the questline you should easily take them out - and head north until you find a large rock by the water. The frog will be just behind it.
Need more help? Our Final Fantasy 15 guide and walkthrough can provide tips on the open-world's many quests and activities. Learning how to get AP fast, EXP fast and Gil fast in Final Fantasy 15 will aid you in the many optional dungeons and tombs - including how to open and explore their locked doors. And if you want to get around easier, you can rent a Chocobo, learn the infinite sprint trick and later in the game, get the flying car Regalia Type F. There's also more to see and do with DLC, such as with Episode Gladiolus, Episode Prompto and multiplayer Comrades packs.
Rainbow Frog location - The Vesperpool
This frog is close to where you pick up the quest from Sania. Jump in the car and head to the western part of The Vesperpool, not far from the enterance of the Merlwood Forest dungeon.
Locate the The Vesperpool - West Bank fishing spot on the west bank, then head north. As you go, there are several small 'islands' just off the shore of the lake. The Frog will be in the middle of one of those.
Once you have found all five Rainbow Frogs, return to Sania at the Meldacio Hunter HQ for a hefty reward of 15,000 EXP and a Ribbon, which protects that party member against all status effects - perfect against Molboro and other nasties.