Canon RF 200-800mm f/6.3-9 IS USM

Widely regarded as an exceptional-value wildlife workhorse — often called an RF 100-400 made bigger and better. Extreme 800mm reach at a fraction of the cost of an L-series prime makes it hugely popular with bird and wildlife photographers, and it's compatible with Canon's RF extenders for up to 1600mm effective reach. Softens somewhat at 800mm wide open but sharpens up stopped down.