Is it possible to have a block without a template in Magento?
Of course yes… in fact, the only predefined block class in Magento that uses a template file is Mage_Core_Block_Template. It is the most used, but not the only block class in Magento.
Other classes in Magento like Mage_Core_Block_Text or Mage_Core_Block_Text_List doesn’t use a template file.