Unfortunately I couldn’t find many guides that actually stated the currencies needed so I’ll put this here for anyone who needs it. Hope this helps.
To exchange currency you’ll need to first clear the first island; Sandy Island. There is no currency on there so don’t worry. Once you move onto the second island Icecap Island, you’ll need to clear the first two areas. Once you clear the second area (named Frosty Flores) you’ll then have a cutscene where a huge walrus emerges from the water in between the two islands. Jump on his stomach to be bounced to the other side and that’s where the first exchange machine is (I believe the island is just called Walrus island). There are many scattered throughout the game, but this is the first example of it. This is where you can actually exchange your first currency at; Yen.
The five currencies are (in order of what is found): Yen, Dollars, Rupees, Pounds and Euros.
The Yen, Dollars and Rupees are found in the second area- Icecap Island
The Pounds and Euros are found in the final area (excluding the DLC)- Eruption island
Now onto the currencies.
*Note: the animals I name are the first occurrences of the specific currency. There are other animals that give some of each currency as well.*
Again there is NO currency on Sandy Island which is the very first out of three parts to this game.
First currency: Yen
Where to find it: Icecap Island; after you clear the first area of it you’ll move on to the second area called Frosty Flores. This is where you’ll encounter an Emperor Penguin bankimal. This bankimal will drop you the yen once it is fed enough. This is also right before you encounter the first exchange machine. Remember with each bankimal you can grab and throw the food they eat near them to make them eat more quickly.
Second currency: Dollars
Where to find it: Icecap island; this is found in the first desert area of Icecap island, once you slide down the sand slope. This first desert area is called Dry Gulch, and the scorpion bankimal drops the dollar currency. There is also an exchange machine in that area as well.
Third currency: Rupees
Where to find it: Icecap Island; this is the last currency you’ll find on icecap island. The last two are in the third part of the game. You’ll get this currency after you clear the first desert area Dry Gulch, where you first found dollars in, and move onto the second area. This second area is called Tumbleweed Towers and it is the camel bankimal that drops the rupees. Just simply exchange it in the machine where you exchanged the dollars.
That is it for Icecap Island, the second area of the game. At this point you should have found 3/5 currencies; Yen, Dollar and Rupee (and the tracker should be at 60%).
Now onto the last island; Eruption Island.
Fourth currency: Pounds
Where to find: Eruption Island; this is found in the second area of this island- called Squirrel Sanctuary. It is the forest snails that drop the pounds. There will be an exchange machine nearby where you can exchange the pounds at.
Fifth currency: Euros
Where to find: Eruption Island; this is of course the last currency and it will be found later on into Eruption Island in one of the last areas; Littertop Rock. The mountain goat will be the one that drops the Euros.
Once you exchange the Euros the achievement should pop.
If you have any questions let me know, hopefully this was more in depth and clear