Singular Rot Grub

Tiny Beast, Unaligned
AC- 8 Hitpoints- 1 Speed- 5ft, 5ft climb
Str- 2 Dex- 6 Con- 10 Int- 1 Wis- 2 Cha- 1
Blindsight- 10ft Passive Perception- 6 Cr- 0
Actions Dive. the target makes a DC 10 Dexterity saving throw when it enters the rot grub’s space or vice versa. If the target fails or take 1 piercing damage from each grub and be infested with rot grubs.
Within 4 hours, the grubs will have started to burrow toward the host’s heart, brain, and other internal organs, eventually killing the host.
The host must succeed on a DC 15 Constitution saving throw every 4 hours or take 3 (1d6) necrotic damage and the target’s Constitution score is reduced by 1d4 points. The target dies if this reduces their Constitution to 0. Otherwise, the reduction lasts until the infestation is cured.
The rot grub infestation can be mitigated by applying fire for 3 turns to the point of entry, causing a combined 13 (3d8) fire damage to the host, or by succeeding on a DC 15 Wisdom (Medicine) check and cutting the grubs out with a sharp instrument, causing an additional 14 (4d6) piercing damage to the host. A greater restoration or heal spell will destroy the grubs, ending the infestation and restoring the lost Constitution.