Look on the left-side menu, almost all the way down. You'll see an option headed by 'Bestiary" with 'Search' under it.
Click on Search, you can than search by 'has meat' and indicate what type.
This will tell you what "player" reported mobs have what you need.
Missions, you just need to go to that planet and read what critters you can get as a mission, it varies from planet to planet, and player to player (depending on skill).
Just some info....