Mosquiton having some trouble with a stake, from the Mosquiton OAVs. This is a key cel, but that doesn't make it immune to art mistakes. The red lining of Mosquiton's cloak is actually painted on the _front_ of the cel. At the bottom right of the scan, you can see a bit of the gray color that the cloak was originally.

I think the art is much nicer in the OAVs than in the TV series, but I've also noticed that even the OAV cels seem to have been done in a bit of a rush. They have more than their share of fixed mistakes, paint splatters, and changes made to the pencils.