Pokémon Go is expanding — but it’s not getting as many extra creatures as some fans were expecting.

Developer Niantic revealed today that it is introducing new pocket monsters to its popular mobile game. Starting today (December 12), trainers may collect Togepi, Pichu, and “select Pokémon” that first debuted in the Pokémon Gold and Silver (Gen 2) games for Game Boy. You will find these Gen 2 monsters by hatching eggs. While it looks like most of the of the 100 new critters that debuted in Gold and Silver still aren’t in the game, this is one of the biggest updates Niantic has made to Pokémon Go so far. And it will likely contribute to the game performing well in the $36.6 billion mobile-gaming industry.

In addition to the hatchlings, Pokémon Go is also getting a special event where you can find a Pikachu wearing a festive hat to celebrate the holiday season. That begins today and runs through December 29.

“As we race toward 2017, we can’t help but feel grateful for the support and reaction the Pokémon GO community has given us, and we’re delighted to start rolling out select Pokémon for them to hatch,” Niantic product director Kei Kawai said in a statement. “We’re also looking forward to celebrating the season with our community by introducing a Pikachu wearing a festive hat, providing Trainers the opportunity to get out and explore their neighborhoods with friends and family as they gather for the holidays.”

The studio also confirmed that it will bring more Pokémon into the game soon.

“The opportunity to hatch select Pokémon originally discovered in the Johto region is just the beginning of how more Pokémon will be added to the game for Trainers to continue their Pokémon Go adventures,” The Pokémon Company International consumer-marketing boss J.C. Smith said.

He noted that millions of people have already collected more than 100 Pokémon, and so now it’s time to start adding more.