Bully. When the Desert Wyvern attacks a prone target, it deals additional damage equal to 7 (2d6) 2d6 .   Cacti Diet. Due to the Desert Wyvern's diet of mainly cacti, it has evolved to gain benefits when eating cactus fruits. The Desert Wyvern can consume a cactus fruit as a bonus action to regain a number of hitpoints equal to 7 (2d6) 2d6 and gain temporary hitpoints equal to 10 (4d4) 4d4 .
Also, the Desert Wyvern has a special sense that allows it to detect any cacti within 300 feet of itself.   Charge. If the Desert Wyvern moves at least 15 feet straight toward a target and then hits it with a horns attack on the same turn, the target takes an extra 10 (3d6) 3d6 Piercing damage. If the target is a creature, it must succeed on a DC 18 Strength saving throw or be knocked prone.   Hyperacusis. If the Desert Wyvern is dealt any Thunder damage, it recoils form the loud noise and has disadvantage on all attack rolls until the end of its next turn.   Tunneler. The Desert Wyvern can burrow through solid rock at half its burrowing speed and leaves a 15 foot-diameter tunnel in its wake. The Desert Wyvern can burrow through sand at it's full burrowing speed and without leaving behind a tunnel.