Rhinoceros (CR 4)

Large Animal
Alignment: Always neutral
Initiative: +0; Senses: low-light vision, Listen +14, and Spot +3


AC: 16 (-1 size, +7 natural), touch 9, flat-footed 16
Hit Dice: 8d8+40 (76 hp)
Fort +11, Ref +6, Will +3
Speed: 30 ft.
Space: 15 ft./10 ft.
Base Attack +8; Grapple +18
Attack: Gore +13 melee
Full Attack: Gore +13 melee
Damage: Gore 2d6+12
Special Attacks/Actions: Powerful Charge
Abilities: Str 26, Dex 10, Con 21, Int 2, Wis 13, Cha 2
Special Qualities:
Feats: Alertness; Endurance; Improved Natural Attack (gore)
Skills: Listen +14 and Spot +3
Advancement: 9-12 HD (Large); 13-24 HD (Huge)
Climate/Terrain: Warm plains
Organization: Solitary or herd (2-12)
Treasure: none

Source: Monster Manual

The rhinoceros is infamous for its bad temper and willingness to charge intruders.

The statistics presented here are based on the African black rhino, which is 6 to 14 feet long, 3 to 6 feet high at the shoulder, and weighs up to 6,000 pounds. These can describe any herbivore of similar size.