Embodiments provide a toy construction element having an outer shell and moving members that can extend from and retract into openings in a face of the outer shell. The toy construction element may have a plurality of pegs for attaching to other engagement elements (e.g., blocks or figurines) and the openings may each be centered with respect to a 2×2 arrangement of pegs on the face. The moving members may be in contact with an actuating member, e.g., opposing arms of a rocking member. As one moving member is pushed down the rocking member may lift the other moving member. Upon attaching an engagement element to the toy construction element, one moving member can be pushed down to force up the other moving member so that the engagement element is released. Other actuating members may be used, such as push-rods or camshafts.