The Brother’s Hunger

The wearer who attunes with this ring gains the ability to cast Arms of Hadar as a level 1 spell
without spending a spell slot. The spell can be
used a number of times equal to your proficiency modifier before needing a long rest.
A pale iron ring with an obsidian gem at its center.
An unnatural hunger overtakes you when wearing this
ring for the first time but dissipates soon after.
Something eager watches from behind the glass.