Ditch the pecs.
If they must keep the dreads, sweep them out the back to either make it look like an Alien head, or crown (don't just have them hanging loose).
Make the mouth more like a normal Alien, but then have the mandibles flare open when it attacks or screams - as it is the mandibles looked tacked on.
Proper dorsal spines - and have four. If it's meant to be a nascent Queen, make them spikes like other Queens.
None of that will fix the acting choices though...