There's no canon or even licensed fictional description of a T-Rogaran anywhere I've been able to find, so I decided to make s**t up and got a little crazy with it, drawing influences from several different sources.
They have a general resemblance to a drider, i.e. insectoid or arachnid abdomen but a thorax and vaguely humanoid head that are held erect. The whole thing averages 2.2 meters tall.
They have a chitinous exterior to shield from radiation on their homeworld, braced with a hollow latticework endoskeleton to deal with the square-cube law.
Four arthropod-style jointed legs. Thorax/torso has arms and three-fingered hands for manipulating objects.
Head looks vaguely reptilian (or turian), as it's covered by a more flexible chitinous material that lets the T-Rogs have facial expressions.
As implied, their vocal parts are completely incapable of producing most English sounds.
They hatch in broods of several dozen at a time. Their non-sapient larvae tend to cannibalize each other down to about six per brood, before pupating into sapient "nymphs" that grow into full-grown T-Rogarans.
"Great War! / And I cannot take more! / Great tour! / I keep on marching on / I play the great score / There will be no encore / Great War! / The War to End All Wars"
— Sabaton, "Great War"
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— Sabaton, "Great War"
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