One of the cooler features about your very own Mother Base, besides picking its color scheme, is that you can effectively design your own emblem. Why is that cool? Well, if you choose to play online, and have one of your FOBs invaded, the invader will see your logo plastered all over your base, containers and even your flag. Not to mention, the logo is also displayed on one of Snake's shoulders.
The logo creator, while simple, has a lot of versatility to it. I mean just check out this thread which has a lot of creative examples.
Some of the animal emblems can only be obtained by carrying out missions in a certain way. I'll outline each emblem, as well as the condition in which it gets unlocked so you can customize your emblem even further.
Chick
You will keep getting this until you complete Mission 06
Chicken
You have used the Chicken Hat at least once in the last three Missions
Foxhound
You completed the last three missions with the "Perfect Stealth, No Kills" score bonus, meaning enemies never entered Combat Alert, you never used Reflex Mode and didn't kill anyone.
Fox
You were not detected in the last three missions, though Reflex Mode is permitted
Eagle
At least 90% of the enemies you neutralized were neutralied with headshots
Puma
Most of the enemies you neutralized was through hold ups
Bear
Most of the enemies you neutralized was through CQC, meaning throw, choke, combo, Bionic Arm punch or kick
Octopus
All enemies neutralized through nonlethal means. Look for ZZZ or STN icons next to weapons to be sure
Mantis
Most of the enemies you neutralized was through slitting their throats after being held up
Bee
Most of the enemies you neutralized was through killing them with lethal handguns
Scorpion
Most of the enemies you neutralized was through killing them with lethal submachine guns
Piranha
Most of the enemies you neutralized was through killing them with lethal shotguns
Doberman
Most of the enemies you neutralized was through killing them with lethal assault rifles
Raven
Most of the enemies you neutralized was through killing them with lethal machine guns, which also include turrets, anti-air cannons, and helicopter gatling guns
Wolf
Most of the enemies you neutralized was through killing them with lethal sniper rifles
Shark
Most of the enemies you neutralized was through killing them with missiles
Orca
Most of the enemies you neutralized was through killing them with lethal throwing weapons like grenades, through grenade launches count as well
Spider
Most of the enemies you neutralized was through killing them with lethal placed weapons
Hog
Most of the enemies you neutralized was through knocking them out by running into them with D-Horse
Hound
Most of the enemies you neutralized was through D-Dog's "Do it" command. You'll need the Battle Dress or Sneaking Suit for D-Dog
Butterfly
Most of the enemies neutralized by Quiet
Ostrich
Most of the enemies you neutralized was by using D-Walker
Tortoise
Most of the enemies you neutralized was through dispatching them with vehicles
Hawk
Most of the enemies you neutralized was through your support helicopter
Whale
Most of the enemies you neutralized was through using the Bombardment option through Fire Support
Bat
Awarded for using various methods to neutralize enemies, though they have to be in exact numbers. That means ten kills with a sniper rifle, ten CQC incapacitations, etc.
