A most captivating sea creature was thrust into the limelight at the tail end of 2015 when the below video was posted on YouTube. The beautiful blue creature depicted was a Glaucus atlanticus, also known as a blue angel, blue dragon or sea swallow. Mind your step if you ever see one though. Despite being exceptionally pretty as well as small and slow-moving, this little sea monster packs a mean punch. Blue dragons are able to eat highly venomous sea creatures called Siphonophorae, including the infamous Portuguese man o' war. The slug then stores the toxins from these creatures in its extremities and so can deliver a very nasty sting when touched. In severe cases, the symptoms are much like a man o' war sting, characterised by excruciating pain, red scars, fever, heart problems and possibly even death. https://www.youtube.com/watch?v=MVXDjtdtj14 Indeed, being easy on the eye is part and parcel of being highly venomous for hundreds of species across the globe all thanks to what is known as counter colouration. To put it simply, the creature makes itself incredibly bright and bold to warn predators of its venom, in the hope that they wont want to have them for breakfast. So lets take a look at some of the oceans other beautiful animals, all of whom do an excellent job of catching prey, fending off predators or even killing humans.