Mystery box - OSRS Wiki

Mystery boxes can be obtained from the Quiz Master random event. Players can choose between 1,000 coins or the mystery box upon successfully completing the event. Multiple Mystery Boxes can be owned at once, and they can be banked.

Mystic cards - OSRS Wiki

Dream Mystery Box, Redemption RSPS Wiki

Mysterious Old Man - OSRS Wiki

Puzzle box - OSRS Wiki

Puzzle box - OSRS Wiki

OSRS - Loot from 46 Mystery Boxes

Random event gift, RuneScape Wiki

Quiz Master - OSRS Wiki

Got a Dragon Spear from the Mystery Box from the Quiz Show random. Did the math, approximately a 1/61,000 chance. Never lucky where it counts :( : r/2007scape

Rok's Chocs Box. - OSRS Wiki