Also known as the Brazilian Spiny-tailed Lizard but that's way less fun!
Weapontails are fairly ordinary lizards from head to toe... but then there's that weapons-grade tail! Short, stubby and abominably spiky. Even their scientific name gets in on the act - Hoplocercus comes from the Greek for "armour" and "tail" while spinosus means "thorny". You got that right!
Weapontails live in dry habitats in parts of Brazil and Bolivia where they feast on insects and retire to underground burrows. When threatened, they run head first into those burrows and use their battle-butt to dissuade predators from poking their heads in.