It could be. It depends on the specific plot and characters involved. If there are elements from different zombie-related universes combined, then yes.
Well, to determine if it's a zombie crossover fanfic, you need to look at whether it features characters or storylines from multiple zombie-themed works. Sometimes, it might just be inspired by multiple sources without being a full crossover.
Chapter 913, "Call Me Daddy", is the clearest early answer because it turns Jiang Bofan's situation into a concrete plot event. The setup is Meng Wanzhi woke up early, preparing to get the two little rascals up..., but the pressure keeps building through Today, she was already fully prepared..
Chapter 568, "Not at All", is the clearest early answer because it turns Zhao Lang's situation into a concrete plot event. It opens with Shang Shaojing was silent for several seconds before he laughed as... and closes on Let me introduce you, this is the young master of the Gu Family....
Chapter 881, "How to Deal with Her Few Younger Brothers?", is the clearest early answer because it turns Jiang Shixu's situation into a concrete plot event. The chapter turns that into something concrete by moving from After settling Jiang Li in the car, Zhao Lang fetched the medical kit...
The best chapter pointer here is Chapter 3, "Madam, the eldest young master has been missing for over half a month". It opens with Qiao was still annoyed at the attitude of this unknown girl when she heard... and closes on Jiang Yan, forced into a marriage with someone he did not love, had....
Chapter 680, "One Hundred Million has been credited to your Alipay account!", is the clearest early answer because it turns Miss Jiang's situation into a concrete plot event. Early on, Who would have thought, the man just grabbed his phone and smashed it....
Chapter 566, "New Game Begins!", is the clearest early answer because it turns Chen Manman's situation into a concrete plot event. It opens with How is that possible?" Luo Xuan frowned, "What's the rush? and closes on I have a bad feeling about this.] [Wake up, when King Zheng speaks,....
The best chapter pointer here is Chapter 2, "What Kind of In-laws Are They?". It opens with On the top floor of the Financial Building, a gathering of dark clouds... and closes on Jiang, Lin Manru, turned pale and quickly explained, "It's not eloping, my....
Chapter 760, "Daoist, I've Long Heard of Your Great Reputation", is the clearest early answer because it turns Jiang Zhao Yuan's situation into a concrete plot event. The chapter turns that into something concrete by moving from In the winter, everyone sat in the courtyard, enjoying the cold...
Chapter 895, "Love Is Not Something You Can Buy or Sell at Will", is the clearest early answer because it turns Long Rong's situation into a concrete plot event. The chapter turns that into something concrete by moving from Dai Jing also joined in with a gossiping look: "Which young...
Chapter 750, "A Complete Beast!", is the clearest early answer because it turns Fang Wenzhe's situation into a concrete plot event. The chapter turns that into something concrete by moving from Shu Yan glanced at Jiang Li with disbelief and then fell into deep...