It's Pony

Annie and Pony's camping trip is in jeopardy when Pony is scared of 'Plants!', then in 'Heston's Coat', Heston loans Annie his coat, but it's only a matter of time before Pony ruins it. (S1, ep 1)

Pony becomes a video game master in 'Game Horse', and in 'Unicorn', when Pony thinks he has turned into a unicorn, Annie uses him to raise money to save their sports court from closing. (S1, ep 3)

Annie tries to curb Pony's inquisitive nature in 'Nosy Pony', then in 'Beatrice', Annie worries that her lonely friend is better at taking care of Pony than she is. (S1, ep 2)

Annie can avoid detention if she can heal the principal's dying plant in 'Horace', then in 'The Boot', Pony causes Annie to lose one of her boots, which she needs for a family photo! (S1, ep 4)