I use PowerPoint for such presentations and have a couple targeted at the Drymarchon genus, not D. couperi only.
Brief up on the natural history, historical and current ranges, reasons the species has been extirpated from historical ranges, such as development, habitat fragmentation, road mortalities, wanton killing and over collection. Children will be mesmerized by the sight of an actual snake in their classroom, which will certainly be the center piece of attention and by keeping each individual topic short, you will better hold their attention.
Your son will gain a lot of points among his peers, should you allow him to hold the snake during your presentation and take it around the classroom for all to obtain a close up view. Just make certain he is aware that some children harbor a great fear of snakes and he should be empathetic of such and keep the snake away from them, as most will warm up to the snake, once they see others interacting with it.
For a fun topic, you can discuss the feeding habits of Drys. I have few that will eat hotdogs without a second thought and mention they would probably eat pizza crust if I offered it, always get a giggle or two.
Good luck,
Jeff
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Jeff Snodgres
University of Arkansas
snodgresjeffreys@uams.edu
501.603.1947