A toy sword assembly or similar device is fabricated of a lightweight and flexible foam material. The assembly includes an elongated blade and handle subpart and a guard part that fits on a guard grasping section of the blade and handle subpart. The blade and handle subpart include interlocking and interfitting formations so that said subparts can be connected together and form an enlarged, three-dimensional, authentic-appearing cross-shaped cross-sectional sword. A planar one-piece guard is provided for cooperation with the assembled subparts. The guard has an internal aperture which is shaped to correspond to the cross-shaped configuration be fitted or mounted from the blade end, fit in the grasping section, be oriented at right angles to the blade and handle subparts and be mounted to the assembled subparts only from the blade end. Several embodiments of swords and similar devices are shown which employ the interlocking formations.