I still remember him..a brown, plain horsd named Poopy. It was during our first MMO, Ultima Online, that I discovered my love for little digital mounts. Poopy lasted for most of my time in Ultima, and I remember that if I died he would would often fight for me, and I would worry that he might get killed.
And one day he did.
I really felt a loss for the little guy. He was a stronger character to me than most of the NPC's and even some of the people I had met in game. He had personality, and he was realistic. If you dismounted, he was still there. He would fight for you, and even die, permanently! I aquired Poopy II shortly afterward, but I always remembered my first real mount.
In Ryzom, I have always had the same mount. He is a strange looking beast, a Mektoub with the hands of a semi-human and the long nose of an elephant. I have always called him Yardnose. Funny thing about Ryzom is not only does your mount stay around and breathing in the world while you are away, but they stay at that point forever. As long as they don't move or get killed, they will stand there breathing. I might skip logging into Ryzom for months, and my mount would have stayed in the last spot I left him, passersby looking at him and wondering who he belonged to. Heck, he's there right now...breathing. Those pixles, that little bit of server code or memory on a hard disk somewhere has existed for several years.
And that brings me to my current favorite F2P game, Mabinogi. I was delighted to find that my horse mount (the fastest type in the game) not only will fight for me, but will die, be rezzed, heal and carry items. I got to name him (named Osheba after my old german shephard) and I can even play AS him! He gains skills, grows old, and can even be re-born! He's always there..I can tell him to "stop" at a certain spot, and he will be there until I return.
The only real drawback is that he will de-spawn after roughly an hour and a half (different pets stay out for different lengths of time) and will need to be put away to recharge his time. Luckily, the amount of time is enough to get real use out of the mount/pet! I can ride him all over, use him to help me fight and when I finally need to "stable" him, it doesn't feel like he is disappearing after every dismount.
I love to grow my character over time. I love to build him/her up slowly, adding to his/her layers as time goes on. In fact, most of my dislike of fast leveling stems from the lack of realistic growth. I want my character to build up some scars, to get knocked back a few times...to struggle. And I feel the same about my pets. I want them to grow with me, to become a true companion, a character in the chapters of my MMO.
I own roughly 10 or so pets now, and besides my horse I have a two-seater Ostrich (for picking up needy passengers, a great way to meet new people), a sled dog named Medicina (because he carries medicine just like the Alaskan dog race dogs represent) that actually pulls a sled when in snow, two small dogs that pick up any items that I might drop or forget to grab when mining or in a dungeon, several silly fun pets and my favorite combat Teddy Bear (I am not kidding) named Rooseph. She's a monster...can take down anything I come across.
You can even program a pretty deep AI for your pets, or use a basic set of rules like "aggressive" or "collaborative attack mode." All in all, the pets in Mabinogi have always reminded me how fun the cash shop is.
But the main reason I like them is that they are always there..I can call one out and they stay with me until they die, just like in Ultima days. They are always at my side, which is important for a soloer. Also, in real life I think of my companion animals as real companions, as constant friends that are willing to go on any adventure with me. One of the reasons I admire the sled dogs of the Iditarod so much is that they not only save their owners life, but are a force of hope for the owner, something to trust and something constant.
It's hard to feel that a pet/mount is constant if you cannot even name it, or if it disappears when you get off it. That's how it happens in most MMOs.