Lecters are large moths that attack the player by firing two homing shots from their wings.
The best way to avoid taking damage from from homing shots is to have them hit the wall behind you. If there is lots of terrain in the room, then hide behind it until the Lecter shoots. Then pop out to kill it.
The name and appearence of this enemy is possibly a reference to the novel/movie The Silence of the Lambs, in which psychiatrist and cannibal Hannibal Lecter assist a female FBI agent in capturing a serial killer whose signature is the chrysalis of a death's head hawkmoth, stuffed into the throats of his victims.