This is one of those sentences where I know all the words, and I know the grammar, but I want to carefully analyze it to ensure I understand how its parts are summed. Specifically, it turns out that
From Pokemon, I’m used to 野生のポケモン (wild/feral), but here Cocoa-san speaks of the rumored 野良 (stray) rabbit.
It’s a shame Cocoa-san’s line 「ダメだよ私！」 didn’t make it into the cartoon. It’s my favorite line of the comic up to this point.
I thought I would have trouble looking up the conjugation in 行かなきゃ, but it turns out there are plenty of helpful resources, including a post on Maggie Sensei:
People who just learned formal Japanese from text books and/or strict teachers may find this difficult because they are not traditionally taught. Actually we use these suffixes very often in casual conversation.
They mean “to have to do something” or “must do something”
First, one needs to know the provisional form (“if X doesn’t go”), which for 行く it turns out is 行かなければ, then add いけない (“must not do”) or ならない. This lengthy string of letters may instead be compressed down into 行かなきゃ. The result is a verb meaning “I have to do VERB”, or in Cocoa-san’s case, “I have to go to school!”
I’m sure it’s worth knowing the longer version, but for now I’ll focus on memorizing the meaning of 行かなきゃ, and go from there the next time I see なきゃ. (It’ll come up again on pages 30 and 37.) ちゃう also appears on the current page.
Count of new cards in Anki for page 29: 15 cards.