You Do Need power plug adapter while traveling from Equatorial Guinea to Senegal.

Here is Why You Need An Adapter

The outlet and plug type used in Senegal are C, D, E and K and in Equatorial Guinea are C and E. This is how they look like.

Equatorial Guinea

In Equatorial Guinea, outlets of type C and E are in use.

Type C

Type E

Senegal

In Senegal, outlets of type C, D, E and K are in use.

Type C

Type D

Type E

Type K