Repeat words and names of reptiles. Practice makes perfect, and toddlers learn through repetition, so you should focus on using the names of specific animals repeatedly. You can also repeat the words describing the various reptiles to help them learn. Such adjectives may include green, slimy, scaly, wet, long or rough.
Use the toddlers' interests. If you have a room full of toddlers who enjoy watching TV, show them videos on reptiles. If your class prefers art projects, allow them to make their own reptiles from clay or draw pictures of their favorite reptile.
Allow the toddlers to explore reptiles with all their senses. Bring in a non-harmful snake or lizard for the kids to touch. This will help make the idea of a reptile more concrete.
Develop games to help them learn. Kids love to play, and the subject of reptiles lends itself to a variety of games. You can hold up pictures and play "name that reptile," or you can create a board game that uses reptile pictures or colors to navigate to the end.