i convinced my DM to make an item of mine into a weapon

simple story. me and two friends play dnd together once weekly. me and party member had just finished killing a bearded devil while we were both at level 2. we ended up looting the corpse for its items, because who wouldn’t want a demonic weapon? we each rolled a d20, with my party member receiving its glaive and me receiving its, drum roll please… its belt. i got just a regular piece of leather. thankfully me and DM have more dark senses of humor, so i somehow convinced him to make the belt a weapon that deals 1d4 bludgeoning damage, with a 2d4 if you roll a crit. the dark thing about it is that it deals 3x the damage to children