VashTheStampede
Dumdum McGee
((We'll go with History in this case))T'anks looks at the drawing, the crude craftsmanship serving to obfuscate the exact nature of its meaning. She glances down at Other Goblin's corpse and then back to the drawing. She distractedly begins to follow Dragmire towards Dude's location, mulling things over in her head...
If your friends have truly been captured by these Goblins, then time is not on their side. But I have no objections to a short rest.
[History/Religion] Check to glean insight into the sketch found on Other Goblin.
T'anks recalls hearing stories about how some goblin tribes, especially on the Sword Coast, have had tales passed down over the years that are used to scare their children into following instruction. These tales include unnerving stories of goblin tribes falling under the control of malevolent beings far more sinister than themselves, and how these evil beings would warp and twist these fallen tribes into something wrong, changed in various ways to mindlessly do the bidding of their new masters.
This drawing could likely be the result of a goblin who grew up traumatized by these stories and has recurring nightmares about these twisted, evil goblins.
That would seem a best case scenario.