Goliath frog
In 2019, scientists learned that the frog does something unusual: It digs pools to lay eggs in.  The scientists think it is the male frog who digs the pool.  Because not all the tadpoles in each pool were the same size, the scientists came to think that frogs lay eggs in the same pool more than once.  The frogs move sand, pieces of plants, and stones almost as big as they are.  They use the stones and plants to build higher walls for the pool.  Scientists saw adult frogs staying near the pools at night to scare away bigger animals that wanted to eat the tadpoles.  Scientists think this might be why the goliath frog is so big: Bigger frogs can move bigger rocks, build bigger pools and scare away bigger predators.