Transquito is a Mosquito (as per the name !) mainly cast in a bronzey brown plastic with some additional purple bits. As such what he looks like in beast mode is essentially a scaled up version of Waspinator (which might also have hampered the toy) with the addition of a prominent spike bellow the head. In this mode he has 6 fixed legs which meet the body at a ball joint. The clear yellow wings on his back flap by moving a lever and can be bent up or down. He has a weapon in this mode - pull back on the levers at the rear of the head causing the head to split in two and the stinger to flip into the gap and to be used as a missile launcher.
At this point the Mega toys were being used to trial vehicle modes for BW TFs: Move the wings out to the sides, fold the wing section back revealing a second face then split the wings in two down the middle and fold the front halves to the sides. What you get is some sort of crawling wingless beast with a huge pincer claw which can be opened and close by a lever on his back. Not the greatest alt mode.
TF to robot (from beast) Flip the missile launcher up. Pull the legs slightly to the sides. Fold the beast head down between the beast legs to form the robot chest and close the beast legs onto the sides. Pull the robot's arms away from the tabs on the insect body and straighten. Split the abdomen in two down the middle. Pull the end of the abdomen nearest the thorax out to the sides by joints at the far end of the toy - you want it so the abdomen halves (lower legs) are sticking out to the sides. Now you can see the screws looking out from the robot hips - you want to hide these. Swing the robot legs up so the upper legs are in a sitting position but the lower legs still point to the sides. Fold the legs out to the sides as far as possible, straighten at the knee and swing the robot legs forward so the solid side of the hips is showing. Rotate each leg in 90 degrees at the hip so the front of the legs is showing. Fold out the feet.
Once again very Waspinator like in form - beast legs on the arms, beast head on the chest, insect wings on the back. This time we do get Jetstorm & Bonecrusher's "head with a weapon in it" in this case the missile fired by a trigger on the head. He bends at the ankle & knee, swivels bellow the hip, the hip bends to the side and moves back and forth. The head can turn but for it to not be looking down when you do it the toy needs to be leaned back a bit. The shoulders are ball jointed, there's a bicep swivel and the elbows bend. Wings still flap via a lever in the back.
Overall: OK, but there's nothing new or innovative here, and the resemblance to Waspinator is so strong they'd have sold more if they'd have coloured it green and called in Waspinator. Big Mos Big Mos keeps the same basic bronze colour as Transquito, the yellow on the wings and the brown of the antennae and legs. But I'm afraid Takara has one of it's periodic moments of repaint madness after that - the purple is gone replaced by Day-Glo green and some bright red. Awful. Bad for the eyes.
Big Mos shipped by himself as Beast Wars Neo C-17 or in VS-17 with Autostinger - the yellow version of the G2 Autoroller Truck.