Lizards are minimally mentioned in the How to Train Your Dragon Book series.
Lizards include many species in the Order Squamata, but exclude other squamate reptiles such as Snakes and Worm Lizards. Lizards have a huge range of morphological, behavioral, reproductive, and dietetic differences. However, all have hard scales or plating made of keratin and a 'quadrate bone' allowing for jaw movement. Most species have four legs oriented outward from the body, rather than downward from the body. Many can loose their tails for various reasons and regenerate them. Some lizards are huge, while others are very small. Some can even glide by extending their ribs.
Lizards do not have a use in the Book series, other than as a derogatory reference for dragons.
In reality, lizards have been kept as pets, skinned for their hides, and used as food.
Sharkworms are described in detail in this book, including using lizards as a metaphor.
|“||Their back set of teeth could shot forward to grab prey, then retreat back, dragging the unfortunate victim with them, as the tongue of a lizard flicks out to catch a fly.||”|
|— Book 3|