Gandalf Pop Up

My friend and I recently bought Rising World and we didn't know anything about it before we got it, besides the screenshots on the Steam page. We eventually figured stuff out, and went mining. We eventually split up, he was digging down, and I dug elsewhere. The weirdest thing that happened was he claimed he saw a pop up of Gandalf that genuinely scared him. He asked if I saw it too, i'm talking to him about it right now and he doesn't sound like he is telling lies. I went down to see if I would get the popup, but I didn't see anything. We thought about it, Gandalf usually says YOU SHALL NOT PASS, so we thought, and we came to the conclusion that maybe it was an Easter Egg that lets the players know that the void is a few blocks down, and that if you DO PASS, you will die, but when we searched we didn't find a void. He later explained to me that it was dark when he saw it so he may have just seen something random when there wasn't anything at all. Please let me know what you guys think, or if you have seen this too. I also now realize it could have been a lighting glitch as the game is still in early access. Thanks,
-Nerf