Here is the full list of all 15 Tembo The Badass Elephant achievements worth 1,000 gamerscore.
You obtained 10 Peanut Butter Jars.
You destroyed all the PHANTOM enemies in a stage.
You rescued all the civilians in a stage.
Your training is complete.
Smash the PHANTOM Lock.
Destroy the first PHANTOM Dome.
Demolish the second PHANTOM Dome.
Obliterate the third PHANTOM Dome.
Defeat the PHANTOM Commander and thwart the PHANTOM invasion.
Collect 99 Peanut Butter Jars.
Rescue all the civilians in a zone.
Destroy all the PHANTOM enemies in a zone.
Rescue all the civilians in or around the island.
Obliterate every last PHANTOM enemy.
Accomplish all of your Missions.