Barbed Servitor

Indestructible
When Barbed Servitor enters, suspect it. (It has menace and can't block.)
Whenever Barbed Servitor deals combat damage to a player, you draw a card and you lose 1 life.
Whenever Barbed Servitor is dealt damage, target opponent loses that much life.

Murders at Karlov Manor

Indestructible
When Barbed Servitor enters the battlefield, suspect it. (It has menace and can't block.)
Whenever Barbed Servitor deals combat damage to a player, you draw a card and you lose 1 life.
Whenever Barbed Servitor is dealt damage, target opponent loses that much life.

Indestructible
When Barbed Servitor enters the battlefield, suspect it.
Whenever Barbed Servitor deals combat damage to a player, you draw a card and you lose 1 life.
Whenever Barbed Servitor is dealt damage, target opponent loses that much life.

Murders at Karlov Manor Promos

If a suspected creature loses all abilities, it will lose menace and "This creature can't block", but it won’t stop being suspected.

A creature can be dealt an amount of damage greater than its toughness. For example, if Barbed Servitor is dealt 3 damage, its last ability causes the target opponent to lose 3 life.

Being suspected isn’t a copiable value. If a permanent becomes a copy of a suspected creature, it won’t be suspected.

If a creature is already suspected, suspecting it again won’t have any effect.

If your life total is brought to 0 or less at the same time that Barbed Servitor is dealt damage, you lose the game before its last ability goes on the stack.

There’s no limit to the number of creatures that can be suspected simultaneously. Suspecting a new creature doesn’t cause other creatures to stop being suspected.

When an effect suspects a creature, it becomes suspected. It gains menace and "This creature can't block" for as long as it’s suspected. It stays suspected until it leaves the battlefield or another effect causes it to no longer be suspected.