Shady Oasis is the last level in Autumn Plains and the last level in Spyro 2 that has a Talisman in it. You'll need all 14 of them in order to reach Ripto and Gulp to get rid of them for good.
Shady Oasis' Intro cutscene has a tiny-winged hippo trying to get a big berry from a bush (a tree???), but then he has to chase after a thief that already has several berries. The hippo manages to get one left behind from the thief and grow huge, chasing the hell out of the thief until his massive size gets him stuck to a wall.
The Talisman task, the final one for this game, is to help Shorty the Hippo get to the center of the oasis containing the Great Berry Bush through the help of the smaller Berry Bushes that can make him huge. No matter what you have to do, just get one of the Berry Bushes to shake so Shorty can bash his way through locked gates and any enemies in his way.
Reaching the end will have Shorty give you the final Talisman: The Mystical Lamp, but there's more to do in this level than just that.
There are two Orbjectives in this level, but I can only do one right now:
1). Right behind Shorty at the end is a purple hippo named Bruno needs your help to retrieve 3 other Lamps from tricky thieves. You chase after these thieves like you chased down the blue, egg-stealing thieves from Spyro 1. They'll even taunt you the same way. Kill them all and take back the Lamps they've stolen, and Bruno will give you an Orb.
2). Right in front of an Invincibility powerup is another purple Hippo who is apparently a girl, Grundy. She needs your help to save her brothers from sinking in the gooey green lava, but you can do this until you've learned how to Headbash.
There's a Mystery Jar here, too. Be sure to mess with that and chase it all the way back to the start of the level. All watch out for metal containers that can only be opening by Headbashing them.
The Outro cutscreen has two hippos noticing that the Great Berry Bush has suddenly lost all of its berries. They found out that a 3rd hippos was feeding on a lot of them, and they were not happy about that. The 3rd one tried to compensate by sharing some of his berries with a 4th hippo.
With all 14 of Avalar's Talismans in tow, nothing was left to stop Spyro from facing Ripto and Gulp!
See me get the final Talisman in Reignited Trilogy, here!: