A device to connect a network node to an RG8 thick ethernet cable without affecting other connected nodes.
A vampire tap has an interface box with a "V" shaped groove along one side. A sharp needle protrudes from the center of the groove. The cable is clamped into the groove by a grooved plate held in position by two thumb screws. With sufficient practise, tightening the screws forces the needle through the cable jacket and into contact with the cable's center wire while other spikes bite into the outer conductor. The interface box has a 15 pin connector to connect to the network node.
The vampire tap is often built into the transceiver, with a more flexible multi-wire "drop cable" to connect the transceiver to the node.