Here is the full list of all 15 Tembo The Badass Elephant achievements worth 1,000 gamerscore.
You obliterated every last PHANTOM enemy in or around this fair island!
You accomplished all of your Missions. You did it all. You are a supreme soldier. WE SALUTE YOU!
You defeated the PHANTOM Commander and thwarted the PHANTOM invasion!
You rescued all the civilians in or around this island.
You obliterated the third PHANTOM Dome.
You destroyed all the PHANTOM enemies in a zone.
You obtained 99 Peanut Butter Jars. I mean, that's a lot of Peanut Butter.
You demolished the second PHANTOM Dome.
You destroyed the first PHANTOM Dome.
You rescued all the civilians in a zone.
You smashed the PHANTOM Lock.
You obtained 10 Peanut Butter Jars.
You rescued all the civilians in a stage.
You destroyed all the PHANTOM enemies in a stage.
Your training is complete.