What is Wolf's reaction when a voice is heard calling, "Rip Van Winkle! Rip Van Winkle!"? What two emotions does Rip feel?

Wolf growls; Rip is apprenhensive and surprised.

"Rip Van Winkle! Rip Van Winkle!" He looked round, but could see nothing but a crow winging its solitary flight across the mountain. He thought his fancy must have deceived him, and turned again to descend, when he heard the same cry ring through the still evening air: "Rip Van Winkle! Rip Van Winkle!" - at the same time Wolf bristled up his back, and giving a low growl, skulked to his master's side, looking fearfully down into the glen. Rip now felt a vague apprehension stealing over him; he looked anxiously in the same direction, and perceived a strange figure slowly toiling up the rocks, and bending under the weight of something he carried on his back. He was surprised to see any human being in this lonely and unfrequented place, but supposing it to be some one of the neighborhood in need of his assistance, he hastened down to yield it.