One of my very favorite things about the show is the way it shows how different Spear and Fang are, yet they care for each other in spite of that. Especially on Fang's side. She's a reptile and she's less intelligent than Spear, so there are multiple moments in the show where she just doesn't fucking understand Spear and how he thinks. Like the entire experience Spear has with the mammoths.
Yet, in spite of her not understanding so much about him, it's clear she cares for him. The scene where they leave footprints on the beach is genuinely very moving. She definitely values him as a living thing.