Herodians
The Herodians are a Jewish faction named in the Markan account of opposition to Jesus. They appear paired with the Pharisees on two distinct occasions — once plotting his death, once attempting to entrap him in speech.
Conspiring against Jesus
Early in Mark's gospel, after the healing on the sabbath, hostile groups close ranks: "And the Pharisees went out, and right away with the Herodians gave counsel against him, how they might destroy him" (Mark 3:6). The Pharisees and Herodians, ordinarily distinct, here act in concert against Jesus.
Seeking to entrap him in speech
Later in Jerusalem, the same alliance returns with a different tactic — verbal entrapment rather than direct violence: "And they send to him certain of the Pharisees and of the Herodians, that they might catch him in talk" (Mark 12:13). The pairing is consistent: the religious party and the Herodian party combining to test or remove Jesus.