My cat's new collar is strange

My cat didn't wear collars. He had always hated them, and as he got older, he became more finicky and cat-like. But in a strange turn of events, it didn't seem like he was finicky anymore. <br><br>About a month ago, I had taken him to the vet for a standard check-up. But something was off about the trip back home. As I looked back into his carrier, he was staring at me. <br><br>"Certainly not normal." I thought, but I didn't think much of it. It was late and I was tired. I put the thought out of my head, and thought about how good my bed was going to feel in a few minutes. <br><br>I brought him inside and let him out of the cage. He usually ran straight for the cat food as soon as I dropped the bag on the counter, but today he seemed more reserved. He walked out of the cage and to my legs, where he began to purr and rub against them. <br><br>"Well, look at that." I thought. I had always assumed that he was just a standoffish cat, but today he seemed different. I tried to pet him as he purred against my legs, but he hissed, took my hand in his claws, and scratched it. <br><br>"Alright, back to usual." I thought. I proceeded to open the cat food, and he ran towards the sound.<br><br>However; when I looked back at him a few minutes later, he had a collar on. It was an odd, metallic color. It was definitely not the collar I had bought for him all those years ago, when he scratched it off a day later. I picked him up, and examined it. There was a small tag on the front that read "do not remove." <br><br>I thought that was a little strange, but he seemed to like it, so I left it. He was actually wearing the collar, so I figured that it couldn't hurt. <br><br>But as the days went by, he started to act strange. He was a lot more affectionate, don't get me wrong, it was nice. But he started to get a little too clingy. One night, I had woken up in the middle of the night to get a drink of water. As I walked out of my bedroom, I saw him sitting in the hall. Staring at me. <br><br>"Eerie." I thought. I didn't think much of it, and went back to bed. <br><br>But the next night, I woke up to get a drink, and he was sitting there again. This time, he was staring at me with his eyes open as wide as possible. I froze. <br><br>After a few seconds, he blinked, and Rubbed against my leg. I let out a sigh of relief and patted him on the head as I went back to my room.<br><br>He didn't sit in the hallway anymore, but he still was clingy. Every time I went to the bathroom, he followed me. I couldn't even take a shit without him in the bathroom. It was frustrating, but I figured it didn't matter. <br><br>I just wish he would stop staring at me.