This was likely a gag to signify the 1000th episode of the One Piece anime. Devil is one of the scariest greens in Usopp's arsenal. It resembles a venus flytrap, but is significantly larger.

Usopp's journey from cowardly liar to confident sniper shows immense growth and inspires others in One Piece story. Post-timeskip, Usopp has outgrown his insecurities, developed Observation Haki ...