The gila monster (Heloderma suspectum) is one reptile that comes with its own mythos. This species has been widely feared in the southwest, and as a consequence, many interesting (often hilarious) myths have sprung up concerning this species, including the idea that their very breath is toxic! Gila monsters are one of only two venomous lizards in the world, the other being the closely related beaded lizards (Heloderma horridum). As such, many states limit the keeping of this species, so check with local laws before purchasing captive bred gila monsters.

Even persons not familiar with reptiles can positively identify a gila monster. Gila monsters are patterned in orange or yellow and black scales that have a "beaded" appearance. This species ranges in size from 9-14 inches (22-35 cm) (Stebbins, 1985). Gila monsters have tongues much like monitor lizards (Varanus sp.) do, which are thick and forked. Gila monster venom is extremely potent, but this animal will not bite unless it is molested. Gila monster venom is delivered via grooves in the animal's teeth, and as such, gila monsters have to chew on their prey items to move the venom into the wound. Sufficed to say, should one ever be bitten by a gila monster, the first order of business is removing the animal. From all reports of gila monster bites, this can prove to be a rather arduous task. The best way to avoid gila monster bites in the wild is to NEVER pick one up. Gila monsters are a protected species in their home states, and there are severe penalties for anyone attempting to capture an animal for a pet or to sell.

Gila monsters are diurnal, and are most active in the spring months when there is an abundance of the gila's favorite food, eggs. Eggs from several different species of ground nesting birds make up the majority of the gila monster diet at certain times of the year. Gila monsters are also known to favor the eggs of the desert tortoise (Gopherus agassizii), a federally threatened species. Other wild prey items include small mammals, such as baby rabbits. Gila monster activity patterns are very similar to the patterns of other desert reptiles. During the hot summer months, gila monsters spend a significant portion of their day underground, during the winter months, gila monsters hibernate. Gila monsters may, as desert tortoises do, have a period of activity during the late summer and early fall monsoon months in the Sonoran desert. Although gila monsters are found in the dry Sonoran desert, they are not adapted very well to the low humidity, as their skin is much more permeable than other desert lizard species such as the chuckwalla (Sauromalus obesus). As such, they seem to prefer days where the relative humidity is moderate to high (50-80%) for their activities.

Gila monsters are not regularly found roaming about their habitat, so they are difficult to view in the wild. I lived in the Sonoran desert for 13 years, and hiked areas in gila monster habitat extensively for 12 years before I encountered not one, but two individuals out in the open a day apart. I was so excited when I spotted the black and orange figure crossing a dirt road that I grabbed my camera and jumped out my truck in hot pursuit (no pun intended). I shot 36 pictures of the gila monster, with 32 shots of the fleeing animal's rear end making up the majority of my effort. When I returned to my truck after this excursion, I realized that in my excitement, I had forgotten to leave the emergency brake on, because my vehicle was now quite far down the hill from where I had left it. The next day, close to the previous sighting, I spotted another gila monster crossing a different road. Both of these animals fled from my attention at a high rate of speed (for a gila monster). Neither displayed any aggressive behavior, with the exception of a low hissing noise. If cornered however, gila monsters will act out an impressive threat display by facing the threat, opening their mouths wide, hissing loudly, and occasionally jumping at their molester. Both of these animals were observed in the morning hours of late May. The temperature was 75 degrees F (24 degrees C) and the humidity was 60% on both occasions. With only 2 sightings in 13 years, I still consider myself lucky to have observed this animal in the wild at all.