Skunk
Skunks are infamous for their defensive mechanism, delivered via two glands, one on each side of its anus. When threatened, the skunk fires a foul-smelling musk from these glands, described as smelling like rotten eggs, garlic and sulfur. Special muscles around these glands allows the skunk to fire the musk with tremendous accuracy.
Hairy Frog
Found in sub-Saharan Africa, the hairy frog has no aquatic stage in its life cycle. Additionally, it has bone claws on each toe, hidden under the skin. When threatened, the frog intentionally breaks its own bones, forcing the claws through its skin used to ward off attackers. However, there is speculation that these toes are climbing aids rather than weapons.
Bombardier Beetle
Spraying its enemies with boiling hot liquid from its body, the bombardier beetle defends itself with a spray which is a combination of hydrogen peroxide and hydroquinone, mixed with water and catalysts. The mixture reaches a boiling point on release, partially evaporates and is noxious enough to kill smaller insects and cause discomfort to humans.
Malaysian Ant
Soldier ants of the species Camponotus saundersi have twin glands running the length of their bodies. These glands contain a sticky poison that the ant releases by contracting its abdominal muscles. The poison covers anything in the surrounding area.