Soul Stalker
24 Achievements
Steam
Gobble
Open the first overworld chest.
9.0%
How to unlock the Gobble achievement in Soul Stalker - Definitive Guide
The chest is in the second area behind the first gate, and is right in the middle. Very hard to miss. This unlocks a character which is required for the fourth gate, but I didn't find the character to be useful, so there's no harm in leaving it for later if that's your preference.
After opening the first gate (see First Gate (90G)), there is an obvious chest up in this second hub area. Open it to unlock this achievement and a new character.