Echo Sequence/Monsters/Latrodectus Mimicus
Latrodectus Mimicus is a giant species of spider that masquerades as prostrate humanoids. They often emit sounds akin to sobbing or wailing - or what they think sounds like sobbing or wailing - and will wait for help from prey. When "help" approaches, they leap up and attack. Though not poisonous and somewhat fragile, the are capable ambush hunters.