Sure is a pretty cat but I don't think you have the breeds right
A highland Lynx is a larger than average cat, but a Himalayan is an average sized cat. There is no way a cat of these two breeds could get the size of a Boxer....my housecat is 15 lbs. Maybe your kitty does have more bob cat in him or something? Or maybe more Lynx? I'm not trying to start trouble, but maybe the person you got him from wasn't being truthful with you.....
Highland Lynx Physical features: (this info came from
www.highlandlynx.com ) The Highland Lynx is the only cat breed specifically developed from two existing feral/domestic hybrid breeds, crossing Desert Lynx cats (a bobcat hybrid breed) and an African Jungle Cat hybrid breed (with Jungle Curls ears). You will note that the head is large but not round, with a full, well-developed, almost square in appearance, muzzle. Prominent whisker pads. Highland's ears are large and set wide apart, usually with feathering and tufts on the tip. Their large, expressive eyes are wide set at an angle, with colors ranging from gold to green, with blue eyes in the snows.Tails may come half way to the ground (like the Bobcat), or may be lacking entirely (as in the Manx), or may be any length in between. Males are larger than females and slower to mature. Males will regularly weigh in at about seventeen pounds. Females are generally smaller, averaging ten or eleven pounds.