Headcanons 

• Gilbert’s body temperature is naturally quite a bit higher than a normal humans, usually around 103F. 
• He has two ‘forms’, one where he has six limbs, with his wings underneath his human arms (not suitable for flying, only used when he needs his hands - usually when he’s eating) and one where he is more harpy-like, with wings instead of arms. His sternum and chest muscles are a lot longer and more pronounced in the latter, which is to allow him to fly.
• He’s not a true monster yet - he’s retained enough humanity to only partially be there. Extreme negative feelings, however, change him closer and closer to a true monster, and only very positive feelings will reduce the effect.
• The more monster-like he is, the more feathers he has. A second pair of eyes also form, however if he has reached this point, he’s extremely close to never going back.
• He really likes to eat children, especially those who are 5-10 years old, and young girls just entering puberty. Eating children is usually counted as a ‘monstrous’ thing to do (it’s actually against his morals! They taste really good, though) and he will generally advance towards being more of a monster far quicker this way.
• Humans are his favourite things to eat, though he does also enjoy rabbits and large birds, as well as the occasional deer.