You Do Need power plug adapter while traveling from Zimbabwe to Lesotho.

Here is Why You Need An Adapter

The outlet and plug type used in Lesotho is M and in Zimbabwe are D and G. This is how they look like.

Zimbabwe

In Zimbabwe, outlets of type D and G are in use.

Type D

Type G

Lesotho

In Lesotho, outlets of type M are in use.

Type M