Note: This is a reference to a video game, 100 Men vs. 1 Gorilla, based on the meme of the same name, which Calli played on stream. During the stream, she playfully claimed that the men her gorilla protagonist was destroying were her fans, the Deadbeats. (I can't see where it has anything to do with The Grim Adventures Of Billy & Mandy. )

zgryphon said:

(I can't see where it has anything to do with The Grim Adventures Of Billy & Mandy. )

Look at the skull near the leftmost Deadbeat's elbow.

bunkhead said:

Look at the skull near the leftmost Deadbeat's elbow.

Ahh. Subtle!