This ability is present in many Bydo units in R-Type Command. At the beginning of the unit's turn, a small amount of HP or one unit is recovered; obviously, this cannot go above the normal maximum. Heal consumes a small amount of fuel, representing organic components expending energy.
This ability was mentioned in many Bydo Tissue experiment ships in R-Type Final, and is the subject of a few test models, such as the B-1C Amphibian, part of the Bydo Test Series. However, since all ships in Final explode with a single hit, regeneration didn't see any use.