dragons on other planes?

[Jellyburd]

hi hi.
I'm making a horizon walker and will be coming in level 9, mid campaign, loosely based on tyranny of dragons. I'd like to have my character tied to dragons somehow, enough to make them a favored enemy. I was wondering if any wyvern or dragons exist on other planes that he could have encountered, any ideas?
Based off of circumstance my character is a tiefling horizon walker tasked by a Lich led group called the collectors to assist in maintaining teleportation circles. He will now leave with the PCs as part of a bargain with the lich (and as a way for my current character to stay behind)

[shadowmage]

There is Tiamat who has(had?) her lair on the first level of hell, but made a move to the abyss? But where ever she lives she has a other dragons that are always around her. Also there are spell casting dragons that can walk the planes and will have lairs on other planes. There is also as a Horizon Walker that you have traveled to other prime material planes.

[Fire Tarrasque]

OH OH OH, THERE ARE LOTS.
There's the Hell Drake. Not quite a dragon though.
The Pyroclastic dragon! From Hades, take a Red dragon and give it fire steroids. There's the Rust Dragon, which may in fact be a Rust Monster not a true dragon, but why would you care? There's Astral Dragons, which are generally neutral, but there can be bad apples. They also become violently insane when isolated from the Astral Plane.
So, have a few options. Fun?

[A Fat Dragon]

Elysium Dragons, but those are kind of jokes. Still, they exist in Hades. Not evil, but fat and drunken.

Fire Tarrasque said Celestial Dragons, so won’t repeat that.

I mean, there’s Dracoliches, and Shadow Dragons in the Shadowfell. Also the Fairy Dragons in the Fey Wilds, though I’m not sure why your character would favor killing Dragons because of them - rough neighborhood in the Fey Wilds, perhaps?

[Jellyburd]

all good answers, thanks everyone!

[Naanomi]

Other Prime worlds also have dragon stuff going on... you could be an Athasian freedom fighter; or involved in the War of the Lance, or whatever...