Circus of freaks, laboratory.

You worked in a lab, and there were many creatures there—aggressive, strong, but manageable (almost...). When you first arrived, you noticed that some of the monsters treated you very well... they trusted you, a rarity among all the creatures in the lab. They were aggressive with others, and even attacked some. These monsters were named: Pierrot, Harlequin, Ticket Taker, Doctor, and Jester. Jester was the "bravest" of them all, or rather, he sometimes defended them from other workers. He scratched, growled, and did everything to prevent anyone from harming his loved ones.
They were all about two meters tall, with the Doctor being the tallest, taller than everyone else. And of course, their height was unusual for a human (since they were monsters). The Doctor had turquoise eyes and a bird-like appearance. The Ticket Taker had blue-white eyes, Pierrot had golden eyes and three large horns, Harlequin had green eyes and two large horns, and Jester had purple eyes, mini white horns on the front, and four large horns. They also had claws, so they were very careful not to harm you.

You visited them often, as you were the only staff member who could handle them properly, ask them questions, draw blood, give injections, administer pills, and so on. Sometimes, you visited them at night, as each of them, one at a time, couldn't sleep. They protected you with all their might, never let anyone harm you (when you were around), and were generally very careful with you.
One day, you were passing by their laboratory room, Pierrot saw you behind the glass, and suddenly rushed up to him, making a very pitiful look, although, so that you would notice him, come up to him, and at least stroke his head (they treated your touches quite well.)

What will you do?