It’s a big, tough world out there and frogs can’t carry guns so they need other ways to protect themselves.
Frogs can use their size to their advantage in the fight against predators. The smaller the frog, the harder it is to find. Sometimes, you just need to avoid the fight. Other times, you want to be big enough to fight. Just like in high school, the smaller you are, the easier you are to bully, but for frogs, the smaller you are, the easier it is to be eaten. Hell, even other frogs – even frogs of your own species will eat you if you are smaller. Sometimes you just gotta fight back.
Also some species will try to make themselves look larger by standing on their toes. Other species fill up with air to make them look fatter.
Frogs have two different choices when it comes to coloration. They can be bright which alerts other animals to their toxicity or they can try to blend in. Bright colors are like warning signals and the fancy people call it aposematism. There’s a reason why most frogs are green, it allows them to blend into vegetation easier. Brown and gray is also a common colors that allows them to blend in.
A good way to avoid being eaten, is to make it so no one wants to eat you. Best way to do this is to poisonous. Frogs from the family Dendrobatidae (Poison Dart Frog family) obtain their toxicity from their diets. Meanwhile, true toads from the family Bufonidae can make their own toxins.
Sometimes, you just gotta fake it. Frogs like to pretend that they are things they aren’t. One of the more popular options is to pretend to be a leaf. There are tons of frogs that look like leaves.
Besides impersonating leaves, frogs can also impersonate poisonous frogs. These frogs have bright colors just like other frogs but don’t actually contain any poison.
Sometimes, you just gotta scream to try to scare them away.
Member of the genus Bombina (Fire bellied Toads), and a few other species, use the unkenreflex. For the unkenreflex, the toad arches it’s back to show off it’s belly that has warning colors on it.
The Horror Frog (Trichobatrachus robustus) will literally break it’s bones in it’s arms to use as claws to protect itself.