Bork's Sleep

As part of the action to cast this spell, make a melee weapon attack using your casting modifier for attack and damage bonuses.  The spell takes effect on the caster's next successful melee attack within 1 minute.  When it triggers, roll 5d8; if the target has fewer current hit points than the roll, it falls unconscious until the spell ends, the sleeper takes damage, or someone uses an action to shake or slap the sleeper awake. 

Undead and creatures immune to being charmed aren’t affected by this spell.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, roll an additional 2d8 for each slot level above 1st.