why not use PLA, itβs plentiful and cheap although am not convinced it safe around a 100 watt bulb for any length of time , Am impressed it stuck to a cold bed for almost two days.
Looks really great!
PET is more clear, PLA is less clear, but also a bit yellow, but for a lamb this looks more warm. It is just what you prefere.
For safety you can better use PET than PLA. PLA does burn with flames and it melts and also the drips keep burning. This is the worst behaviour you can have with plastics. PET is behaving better.
PLA is biodegradable, so from environmental view better than PET.
But if you use a lightbulb that does not get so hot, like a led lamb, then both materials can be used.