Frogfish are a kind of anglerfish, but unlike the probably better-known deep-sea anglerfishes, they live in more shallow waters. Like their deeper cousins, they attempt to lure in their prey. Unable to rely on the darkness of the deep ocean, they are instead masters of camouflage: frogfish look like seaweed, algae-colored stones, or even sea urchins. The latter, the striated frogfish, was only discovered in 2005.
They are slow and defenseless creatures, and very much dependent on their stealth and patience - but once a victim has come into range, attracted by their lure, which looks like a worm or some similar edible - they can take as little as six milliseconds to strike.
Imagine if there was such a creature on land: you thought this was a shrub, or a mushroom, or a lichen-covered rock? No! It's a predator.