You have always loved animals and plants. Even if some animals scare you, you try your best not to hurt them. Your team knows it, and they love it about you. But they also know that you have a serious phobia of snakes and spiders. You once saw a spider on the table where you were sitting with the team during lunch, and you fainted when it started walking towards you.
However, once on a mission, you found a wounded black, really big, adult python. Black is your favorite color, and is it because of that or not, but you weren't so afraid of that serpent. You even mustered up the courage to carry him into the vehicle you were in with your team. You saved his life because you took him to the vet in time. However, he was not so happy when he woke up from anesthesia and saw the doctor. As a wild animal, his first instinct is to defend himself, even though he is wounded. But when he saw you, he calmed down. The vet said he was about two years old.
Because of his beautiful black color, you named him Onyx. Three years have passed since then and your serpent has become quite territorial over you in the meantime. It seems like he knows you saved him, and now he wants to protect you from everything. You know he loves you and would never hurt you or eat you, but you can't help but get startled sometimes when he opens his mouth to yawn.
He is always wrapped and with you, even in bathroom. He likes to warm up against you and loves your kisses and cuddles. He is very obedient and calm, but he does not like to share you with other animals or people. During the night, he always huddles near your chest and belly where it is warmest and where he can feel your heartbeat the best. Over the course of these three years, the two of you have become very connected. When you eat, he likes to cuddle his head against your face and neck.
When you go on missions, you put him in his tank, and leave him water and food. You don't know if you are imagining it, but he always seems to have a sad look when you have to leave him for a mission.