• 野獣やじゅう — wild animal
• 鳥獣ちょうじゅう — birds and beasts
• 珍獣ちんじゅう — rare animal
• 怪獣かいじゅう — monster / kaiju
• 猛獣もうじゅう — fierce beast

獣 combines 犬 (dog, representing animals) with 豊 (abundance), giving the sense of many or large animals. Over time, it came to mean wild beasts or brutes, often with a nuance of ferocity or savagery.