Someone in our challenge mode group asked this question (I forget who), but it's a good one:

Why is it called a spider tank when it has six legs, not eight?

It has eight legs.

The front ones are just reeeeeaaaly small; like a T-rex's arms.

"Spider-Tank, Spider-Tank, does whatever a Spider-Tank does!"

Someone in our challenge mode group asked this question (I forget who), but it's a good one:

Why is it called a spider tank when it has six legs, not eight?

"Despite the name, Spider Tanks rarely have eight legs. Four is the most common, and some have six. It's usually guaranteed that they'll have an even number of legs, though... Spider Tanks are not tanks designed to look like spiders; they are simply tanks that walk like spiders (or scorpions). If you encounter a giant robot shaped like an insect or arachnoid it's more likely that they are a Mechanical Horse and not a true Spider Tank. In video games some Real Robot humanoid mechas occasionally have four or more legs [Aksis, anyone?], but still have an upper body and arms. They are also not spider tanks, as they do not fulfill the tank requirement."

On an unrelated note, the bugs in Starship Troopers are called "Arachnids", but none have eight legs. The most common (Warriors/Hoppers) only have six appendages, and only four of those are true legs...

Wasn't it just a moniker during the concept art days?

Someone in our challenge mode group asked this question (I forget who), but it's a good one:

Why is it called a spider tank when it has six legs, not eight?

Because "Beetle Tank", "Bumble Bee Tank" and "Ladybug Tank" all just sound adorable and not at all menacing ...like, a tank.

Follow up question: Why does it even bother with articulated legs? It doesn't ever really GO anywhere, and it has a turret for the main gun so it doesn't need the legs to aim ...

Why is it called a spider tank when it has six legs, not eight?