I find it incredibly ironic you feel the need to say the difference between arachnids and insects yet you can't tell the difference between a fish and an aquatic mammal.I like Sergals in the main, but I'm never quite sure what the copyright status of them is. Lots of people seem to draw them, but they are a recent creation and are technically still owned by their creator; maybe there's some kind of open license attached to them that I don't know about?
Oh yeah, and Joltik? Clearly not an insect for one, it's only got four legs. For another, ticks are arachnids.