It would appear that they have a built-in resistor, although I wish the idiot that wrote that spec sheet would have said so...
Are you planing to "pulse" these with much more than 12V applied? My take is that if driven from either 12ADC or 16VDC, the current will stay within spec.
It's going to running off around 12V - 13.5V. Pulse range is variable from 100ms to 1 second, the pulse width will be a lot wider than the 10ms stated.
So will 8 of these be more than 800mA max IC for the transistor do you recon (when turning on being too much and breaking down the transistor)? Or do you mean the 20mA spec stated?
No, if you wire them to 16VDC, the current will be only 20mA each. If you PWM the 16V, the average current will be lower than 20mA each. If you parallel eight, then the total current would be 160mA on DC, and proportionally less on PWMed DC.
Because they have a built-in resistor, the only way to drive them at their peak current rating would be to pulse them with ~75V.