Marco/Rachel
From Fan History Wiki
According to moriath on LiveJournal [1], between 1998 and 2000, the Animorphs fan fiction community was very wanky. moriath attributed this to the demographics of that fan fiction community at that time. Fans had started reading the books in 1996 and had several ideas about things should be and quickly developed their own fanon. Marco/Rachel fans, which was a non-canon pairing, found themselves in conflict with Rachel/Tobias fans because the latter was canon and some people didn't like seeing them broken up.
