SOLVED Sci-fi for children or YA - a group of friends find an alien who gives them powers

[Mona]

This was a book that got me hooked on reading. Basically floodgates open after this one. I read this book in 2005 but it was a library book and pretty worn out (it could have been first published in the 90s). I only remember bits of plot: a group of friends (kids, perhaps younger teenagers) run into a stranded alien who gives them powers. I think that one of them could turn into an animal but I'm hazy on details here. I only have one scene in memory when the friends were running around and testing their powers with the alien explaining them. The alien was fighting some bad guys and the friends offered to help. It was a first book in a series but I've never read it beyond this point and don't know how many books were written. I moved soon after finishing the first book and the other library did not have them. The name of the book has been bugging me ever since and often think about it as the 'One to get me reading' (I was a non-reader before that).

[Kamilla]

Sounds like Animorphs by K. A. Applegate

[Mona]

Kamilla, I think you are right! Thank you so much!

[Kris]

Glad you found your book, Mona.

The Invasion (book 1) of the Animorphs series by K.A. Applegate - Kamilla's find.