Hey - at least those random mystery explosions were the most realistic fx of all time. Cool. 
Gila monsters are dopey, slow critters and when my folks moved here one hung around the townhouse they were renting. He would just sweep it into a box and release it in the wild nearby. Word got around the area, and elderly people (it was mostly a retirement area) would knock and ask him to please move the Gila monster in their carport. He always did.
A few years ago at work I walked into the back dock area and there was a clusters off employees in a half-circle around a poor Gila monster which just wanted to get away. It eventually started climbing the stucco wall. I had no idea they could do that! The maintenance guy got a bucket and a mop, knocked it into the bucket and took it out into the desert to release it.
The basic view of them here is “dumb, slow critters and if you harass the poor thing enough to get bitten, you deserve it”.
Apropos of little, since as a child I couldn’t make out the words to “Hava Nagila”, I used to sing “Monster; a Gila Monster; a Gila Monster…”
For me, it was “Have a tequila! Have a tequila!”
I took the liberty of posing the question of the unknown kaiju in “Midnight Cowboy” to some kaiju experts, and the answer is ‘Skydon’ from the ‘Ultraman’ episode ‘Present from the Sky.’
Thumbs-up emoji.
The plastic toys in your pic are from Ultraman, but they aren’t the monster in Midnight Cowboy. They’re toys of Gabora, from an earlier episode.
One of those toys ended up in a bag of plastic monsters purchased by Gary Gygax for use as a figure for the table top game he was designing, and ended up becoming the iconic D&D monster, the bullette. Other D&D creatures inspired by that same bag of cheap kaiju knockoffs included the rust monster and the owlbear.
