[Blue Bowtie]

As for the air exiting the defrost outlets only, verify the vacuum source to the HVAC damper control head. It's likely that the vacuum supply tube has fallen off, deteriorated, or left disconnected after some other service. You should be able to hear the vacuum porting to the various damper controls when changing the system from defrost to vent to heat to AC.

There may have been fan or fan motor damage when the lizard took up residence. Failing bearings will prevent the motor from reaching the correct speed and will reduce air flow. Another potential problem is contamination on the upstream side of the evaporator, and your lizard friend may have contributed to that by trying to build a nest in there.