I defined humanoid as standing upright on 2 legs with two arms and a head on top. I define gaseous as gaseous. And define aliens as intelligent beings and thus people, thus leaving out many animals.
Star Trek the Original Series or TOS:
"The Cage" Original pilot film. There are a few glimpses of strange lifeforms in other cages, but we don't know if they are people or animals.
"Charlie X": The Thasian says:
So maybe the true form of the Thasians counts as non humanoid and non gaseous..
In "The Squire of Gothos", there are intelligences which look like energy beings. I don't know if that is different enough from gaseous to count as non gaseous.
in "Arena" when aliens contact the Enterprise a moving multicolored geometrical pattern is seen on the screens. Later an alien appears who looks like a (human) boy to Kirk. But it unknown which, if either, is the real form of those aliens.
In "This side of Paradise" there a plants which might be intelligent or not.
In "The Devil in the Dark" there is an intelligent silicon based lifeform which sort of looks like a pile of rocks with a few tentacles.
In Errand of Mercy" there is a species of energy beings looking like glowing balls of light.
In "Operation Annihilate!" there are probably intelligent beings which look vaguely like flying pancakes or like more disgusting flying objects.
In "Catspaw" there a pair of very strange looking aliens.
In "Metamorphosis" there is being which is:
In "Obsession" there is a creature, intelligent or not, which seems to be a cloud of gas and thus not
satisfy the question.
In "Wolf in the Fold' the possible nature of the murderer is discussed.
"The Gamesters of Triskelion" are brains in transparent containers. The brains look similar to human ones, but I have no clue what their original bodies were like.
"The Immunity Syndrome" features a giant space amoeba, 5hough it probably isn't intelligent.
In "By Any Other Name" Spock remembers something from his mind meld with a Kelvin who took a human form.
In "Specter of the Gun" the Melkotian appears to be a floating head and neck.
There seems to be an energy being in "The Day of the Dove".
The Tholians in "The Tholian Web" appear to be crystals.
The spirts of dead Zetarians appear as lights in "The Lights of Zetar".
And In "The Savage Curtain" the Excalpians look like they are made of rock.
Star Trek the Original Series or TOS:
"The Cage" Original pilot film. There are a few glimpses of strange lifeforms in other cages, but we don't know if they are people or animals.
"Charlie X": The Thasian says:
And the form which the Thasian took to communicate with humans, and thus a more human looking form than its real form, was a giant floating transparent green human head.
So maybe the true form of the Thasians counts as non humanoid and non gaseous..
In "The Squire of Gothos", there are intelligences which look like energy beings. I don't know if that is different enough from gaseous to count as non gaseous.
in "Arena" when aliens contact the Enterprise a moving multicolored geometrical pattern is seen on the screens. Later an alien appears who looks like a (human) boy to Kirk. But it unknown which, if either, is the real form of those aliens.
In "This side of Paradise" there a plants which might be intelligent or not.
In "The Devil in the Dark" there is an intelligent silicon based lifeform which sort of looks like a pile of rocks with a few tentacles.
In Errand of Mercy" there is a species of energy beings looking like glowing balls of light.
In "Operation Annihilate!" there are probably intelligent beings which look vaguely like flying pancakes or like more disgusting flying objects.
In "Catspaw" there a pair of very strange looking aliens.
In "Metamorphosis" there is being which is:
Hydrogen is usually a gas, but ionized hydrogen can be considered a plasma, and thus in a different state of matter.
In "Obsession" there is a creature, intelligent or not, which seems to be a cloud of gas and thus not
satisfy the question.
In "Wolf in the Fold' the possible nature of the murderer is discussed.
"The Gamesters of Triskelion" are brains in transparent containers. The brains look similar to human ones, but I have no clue what their original bodies were like.
"The Immunity Syndrome" features a giant space amoeba, 5hough it probably isn't intelligent.
In "By Any Other Name" Spock remembers something from his mind meld with a Kelvin who took a human form.
In "Specter of the Gun" the Melkotian appears to be a floating head and neck.
There seems to be an energy being in "The Day of the Dove".
The Tholians in "The Tholian Web" appear to be crystals.
The spirts of dead Zetarians appear as lights in "The Lights of Zetar".
And In "The Savage Curtain" the Excalpians look like they are made of rock.
