Actually, the only reason for exploration robots to be cute is that building them will require the taxpayers to pay for them. People will pay to save spotted owls, whales and dolphins. They won't pay to protect skinks, voles and vultures, though they also are a part of the natural scheme of things.
Robots should look sleek and clever, but I suppose they could be cute, like Wall-E. But Wall-E's girlfriend robot was also pretty cool. A robot that resembles a transformer , particularly the villain transformers, would probably not be as well received a design.
Most of the things people create do not look humanoid. You can't fix a human being with a screwdriver and a socket and ratchet set. "standard tools" are generally used with metal objects.
Any device that operates on Mars or an asteroid is going to be operated with a remote, isn't it?