Bill Myers 
Yikes!!! [EPUB ebook] 

In an effort to find the last of the fuel ingredients for their time pod, 23rd-century goofballs Tuna and Herby transport themselves to Africa. Unfortunately, they also transport TJ Finkelstein and half of her 7th-grade science class, including TV star Hesper Breakahart and dreamy Chad Steel. In the jungle, the Time Stumblers’ usual mayhem jumps to a new level as Herby is adopted by a mother gorilla, Tuna is transformed into an ostrich chick, and the students are taken in by an African tribe. When Hesper tries to escape by leaping into a raging river, TJ finds that it’s time to begin showing the leadership qualities that Tuna and Herby claim she’ll have someday as a world leader. Thanks to her, everyone makes it home safely, and the Time Stumblers fuel up their time pod, leaving with laughter, tears . . . and one last zany surprise for TJ.