What is it mean Its deadly tendrils are searching ahead feeling their way forward in long yellow wisps scenting you for you?

The given sentence is describing a creature or entity with "deadly tendrils" that are searching ahead, feeling their way forward in long yellow wisps. These tendrils are "scenting" the person being addressed ("you") for "you".

Based on this description, it seems like the creature is using its tendrils to sense and track the person's presence or scent. The mention of "deadly tendrils" and "scenting you for you" suggests that the creature is potentially dangerous and is actively seeking out the person for some purpose.