Leechrune (5e Trap)
From D&D Wiki
When a spellcaster moves within 5 feet of a leechrune, it must succeed on a DC 13 Wisdom saving throw or be leeched for 1 minute. During that time, they take 1d6 necrotic damage per level of spell when they cast a spell of first level or higher. A successful DC 17 Intelligence (Arcana) check identifies the rune.
A successful dispel magic (DC 13) cast on the rune destroys the trap.
A leechrune could also be attached to an arc axe or some other kind of trap.