Lethal. Fireflies produce lucibufagins — defensive steroid toxins that are acutely poisonous to bearded dragons and cause rapid death, often within minutes of ingestion. There is no safe amount and no antidote. This applies to every firefly species regardless of whether it visibly glows. Never feed any wild-caught insect, and be aware that dragons kept outdoors in enclosures during summer evenings are at real risk if fireflies can get in.

Contains persin, a fungicidal toxin that's dangerous to many animals including bearded dragons, potentially causing cardiac and respiratory distress. Every part of the plant — fruit, skin, pit, and leaves — should be kept away from the enclosure. There's no established safe amount.

Extremely high in oxalic acid, concentrated heavily in the leaves but present throughout the plant. Can cause acute kidney damage and calcium deficiency even in small amounts. Never feed any part of the rhubarb plant.

Not acutely toxic, but very high in oxalates that bind calcium in the gut and actively work against everything the calcium-dusting routine is trying to achieve. Feeding these regularly is a common, avoidable contributor to metabolic bone disease. Fine as a rare, occasional addition — never as a staple or daily green.

Contain thiosulfate compounds that can damage red blood cells and cause anemia in reptiles, similar to their toxicity in cats and dogs. Never intentionally feed, and check that any pre-mixed salad greens haven't been cross-contaminated.

Not toxic, but almost pure water with negligible nutritional value — filling a dragon up on iceberg lettuce displaces the calcium-rich staple greens it actually needs. Skip it entirely in favour of collard, mustard, or turnip greens.

Any insect from your garden, field, or outdoor space carries pesticide residue, herbicide contamination, and parasite risk. There's no reliable way to test or clean a wild insect sufficiently. Only feed captive-bred insects from a reputable supplier.

Widely marketed as "reptile safe" because it was assessed for dogs and cats — it is not safe for reptiles and appears on the Reptiles Magazine toxic plant list. It also needs humidity levels well above what a bearded dragon enclosure should run. Avoid.

Contains calcium oxalate crystals that irritate and swell the mouth and throat on contact — a real risk for a species that grazes on enclosure foliage. Also needs more humidity than a dragon enclosure should have.

Contains calcium oxalate crystals and is toxic if grazed on. A moisture-loving plant that would also push enclosure humidity well beyond what suits an arid-adapted species.

On the Reptiles Magazine toxic plant list. Contains triterpenoid saponins and falcarinol, both toxic on ingestion. Common in gardens and sold as terrarium climbing plants — do not use given how readily dragons graze on foliage they can reach.

Extremely toxic to virtually all animals. Contains cardiac glycosides (oleandrin) that cause heart failure even in small doses. One of the most dangerous ornamental plants — keep it and its clippings entirely away from any dragon enclosure or outdoor basking area.

One of the most toxic plants to animals in general. Every part — seeds, leaves, roots — contains cycasin, causing severe liver failure. Despite looking like a harmless ornamental palm, even a small ingested amount can be fatal. Never place near any reptile enclosure, indoor or outdoor.

Contains grayanotoxins, which disrupt sodium channels and can cause serious cardiac effects if ingested. Common garden shrub — keep any outdoor dragon time well away from it, and never use clippings as enclosure decor.

The entire genus is unsafe. All species produce a milky latex sap that causes severe burns and irritation on contact and is toxic if grazed on — a real risk given how much bearded dragons investigate and nibble plant matter in their enclosure. No Euphorbia species should be used.

Spines puncture and cut reptile skin, and eye injuries are a real and common risk from an active, curious dragon investigating its enclosure. If you want a cactus look, use spineless succulents like Haworthia or a smooth-stemmed Rhipsalis instead.