You do so by going to the mod’s PrimalGameData_BP, scrolling down to remap NPC, select From: RexCharacter_BP To: your new bp. As for summoning it, say for example your new dino is “Rex_character_BP_Child” you summon it in game with “cheat summon Rex_Character_BP_Child_C”; Alternatively you can take a peek at a spawner inside Maps/TheIslandSubMaps/PersistentGameplaySublevel_DinoSpawns and make your own spawner in a test map.