Altaria is hands down one of my favorite Pokemon not just from gen 3, but of all time. Not by virtue of its stats or competitive value though, since it is arguably the weakest of all the fully evolved Dragon types, but just because I love it's design. It's a giant blue bird with clouds for wings which is both creative and adorable. It's pre-evolution Swablu is also mega adorable, and according to its early Dex entries it cleans surfaces with its wings and then washes them off in a river. That is an adorable viral video waiting to happen! I also remember the one Swablu from the anime that got lost from its flock that May ended up taking care of, but sadly did not catch since it reunited with its flock by episode end. Why!? Those two were so perfect for each other and Swablu->Altaria would have complimented her team perfectly!
https://www.reddit.com/r/pokemon/comments/b6icd8
Altaria was so popular it even got a mega evolution in ORAS which somehow made it even floofier, gave it Dragon/Fairy typing, and made it a mainstay threat in the metagame at the time.
Sadly mega evolution is gone and Altaria sadly faded back into obscurity. But I however will keep my love alive for this fluffy cloud bird even if competitive players dunk on it.
Why is this Cloud Bird a Dragon?
Ability: Natural Cure
Item: Leftovers
Nature: Impish
EVs: (HP 252) (Def 152) (Sp. Def 104)
Tera Type: Dragon or Steel
Moves:
Dragon Dance
Roost
Dragon Claw
Earthquake
Set Details:
A bulky sweeper? Yeah, the basic idea behind this set is to set up as many Dragon Dances as possible while relying on Altaria's natural bulk and Roost until you have enough speed and power to become a surprise threat. Dragon Claw is your most reliable STAB and Earthquake is your best coverage option against the Steel types and at least most Fairy types. Leftovers provides extra recovery, Natural Cure is useful for shedding status afflictions provided you are okay losing your stacked Dragon Dances, stat investment goes all into bulk (Feel free to tweak the numbers as needed), and Tera typing can go to either Dragon for extra power, or Steel to make you a better defensive type and a counter against opposing Ice, Rock, Dragon, or Fairy types.
Alto Aria of Annihilation
Ability: Natural Cure
Item: Leftovers
Nature: Bold/Impish
EVs: (HP 252) (Def 152) (Sp. Def 104)
Tera Type: Steel
Moves:
Perish Song
Fire Spin
Roost
Protect/Dragon Claw/Will-O-Wisp/Cotton Guard
Set Details:
A Perish Song trapper. Set up Perish Song, trap the opponent using Fire Spin, and Roost keeps you healthy and allows you to stall for turns. The last moveslot is a matter of preference. Protect burns an extra turn and allows you to scout, Dragon Claw gives you at least some offensive presence if Taunted, Will-O-Wisp punishes physical attackers which helps your teammates if you fall early, and Cotton Guard boosts your physical defense to absurd levels making a physical KO against you a chore. Leftovers for passive recovery again, bulky stat build, Natural Cure sheds unwanted status once you swap out, and Steel Tera for better defensive typing against key counters.
I am still a proud Altaria fan even if it gets snubbed within its own generation by Flygon and Salamence, and continues to be snubbed to this day. It's cute, it's fluffy, it sings beautifully, and I am a proud owner of a golden shiny one. So the competitive players can bite me!