Composition looks quite simple, colors are monotone, it would benefit if you drew a silhouette of dragon as well.
Very nicely drawn, fitting to standard icons, a bit static, could use more
dramatic shading to give implications about the dragon. Could be brighter.
It is drawn well, but it isn't cohesive with background and it appears still. Less arbitrary shading is my suggestion.
It is bit simple but it is done well. Nice color transition, it uses a lot of colors that worked out well together. Fitting with standard icons.
Icon set approved.