After you get the green hreo mask, put it on and talk to the little boy in the fossil stadium. He will give it to you.
go to the fossil guild and talk to the lady on the right and that is the mask salon then select the mask you want to wear and then you have a mask on yourself
warning! spoiler alert! \the blue,green,and pink one cost 100dp, you get the red one for free, you can buy the hare mask,fossil girl mask,and the samurai mask at different points in the game, i know you can get a dropping mask from that dropings guy, after you beat the game, you go to bb brigade base to do the puzzle, in which you get bonyard's mask, and a staff there will give you a bb goon mask
Give them to a guy in the hare club next to the shop thing
go to the mask lady in the guild area.
Feed the snow monster snow berries
You have to go to Seafloor Cavern and wear the Orange Mask.
iin the donation point center for 100 dp
No but you can send fossils from fossil fighters to fossil fighters champions.
wear the officer mask then open the door
Yes! You can send fossils from fossil fighters to fossil fighters champions via the fossil cannon, located in Ribular town in Fossil Fighters Champions.
right after you go past the door to the right