They Only Pray Three Times a Day
The video above explains this concept well too. This is a huge and baseless misconception about Shia Muslims because they have to pray five prayers a day too. They take the liberty of praying Zuhrain (Zuhur + Asar) and Maghribain (Maghrib + Isha) at the same time. This finds logic and reasoning in Sunnah as Prophet Muhammad (PBHUHH) also did the same at many times, even without a reason.
They Pray to a Horse
The horse you see in Shia Islam is symbolic to the horse owned by Imam Hussain in the Battle of Karbala. This horse was extremely loyal and guarded Imam Hussain’s body after the battle as well. Shias respect his loyalty towards Imam Hussain and that is why symbolically represent it. The original name of the horse was Murtajiz but it is also called Zuljanah. Shias do not pray to it, they do not eat its leftovers and they do not bow down to it.
This is merely a symbolic representation to the real horse and is remembered for its loyalty.