Whisper Man

The Whisper Men were a group of featureless beings that appeared to serve the Great Intelligence. They kidnapped the Paternoster Gang — Strax, Vastra and Jenny Flint — forcing the Eleventh Doctor to travel to Trenzalore and face his fate. (TV: The Name of the Doctor)

In one instance, they referred to themselves as "the Intelligence," probably indicating they were a manifestation of it like the living snow. (HOMEVID: Clarence and the Whispermen)

Appearance
The Whisper Men could morph into the appearance of Walter Simeon at will, and much like the human embodiment of the Great Intelligence, seemed to be hollow on the inside, or unreal. They moved slowly, and lacked features, except for extremely white faces with blackened skin around their mouths and sharp teeth. They had angular faces with vague depressions where eyes should be, and exaggerated chins and cheeks. They wore the same Victorian garb as the Great Intelligence's form as Walter Simeon. (TV: The Name of the Doctor)

Abilities
When struck by Strax, one simply appeared to evaporate where hit, and then reformed. They could also pass their limbs through flesh, when instructed by the Great Intelligence to stop the hearts of the Doctor's friends. It was stated that they could kill with a whisper and they spoke in rhyming couplets, although their mouths did not move in sync with their speech. They appeared to hiss at their victims, and travelled in small groups when attacking. (TV: The Name of the Doctor)

They could also disappear and reappear in different places. With Clarence DeMarco, they disappeared from outside the jail cell and reappeared inside his cell, in which they gave him information that he could use to save his life. (TV: Clarence and the Whispermen)

Rhymes
The Whisper Men typically spoke in rhyming couplets usually containing eight syllables in iambic tetrametre per line, with the exception being the aforementioned interview with DeMarco.

The first was heard as Vastra and Jenny fell into the trance:


 * The trap is set. The Doctor's friends
 * Will travel where the Doctor ends

The second was heard when the Doctor and Clara were cornered at the tombstone bearing River Song's name:


 * This man must fall as all men must
 * The fate of all is always dust

The third was heard after the Doctor and Clara fell into the secret entrance to the Doctor's tomb:


 * The man who lies will lie no more
 * When this man lies at Trenzalore

The fourth was heard when Clara had her memories awoken while climbing inside the destroyed TARDIS:
 * The girl who died, he tried to save
 * She'll die again inside his grave