You Do Need power plug adapter while traveling from Guyana to Croatia.

Here is Why You Need An Adapter

The outlet and plug type used in Croatia are C and F and in Guyana are A, B, D and G. This is how they look like.

Guyana

In Guyana, outlets of type A, B, D and G are in use.

Type A

Type B

Type D

Type G

Croatia

In Croatia, outlets of type C and F are in use.

Type C

Type F