I have seen players with a baby dragon as pet in Stendhal.
How do I get one?
I won't give a spoiler, but this much I can tell: You can get the egg for a baby dragon via solving a quest. Someone will then hatch this egg for you, and you will have a baby dragon then. For spoiler information you can visit the quest section on the stendhal website.
There is a spider quest in the magic city school see morgrin, you have to kill spiders. Do it alone at about lvl 40 with good atk and def, take a home scroll and antidotes, potions, perhaps some pizzas.
If someone already killed the spiders which are in a square hole to the top of the hallway, they respawn very slowly, could take 30 minutes for them to come back (there are 3).
After you get the egg, go back to the cave to the right and just above bears and black bears one screen to the right of the wheat field in semos plains. You have to go straight up in the cave passing the green dragon and to the right go down a short passage to the woman who hatches dragon eggs. It takes several days to hatch.
The baby dragon will fight but it is easy for it to get killed, you could put it on another character you keep logged out until you have time to let it kill low level monsters that don't turn on lower level players or summons. They are a lot of fun and eat meat.