What is a similarity between Animalia and Plantae kingdoms?

Well to be precise both are living entities composed of fundamental units building them up called cells however thd two major domains of life, namely the Plants and Animals have huge differences. It starts at the cellular level from the presence of a rigid cell wall in one domain while its absence in the other and so on it continues to the macroscopic difference of locomotion of which plants as a whole are incapable. Ofcourse some hydrophytes do float on water and move but that's a passive movement.

Both of their cell are Eukaryote.