Assume the following x86-32 instruction:

add ebx,1

There are (at least) two ways to assemble this opcode:

81 c3 01 00 00 00

or

83 c3 01

The first keeps 1 as a 4 bytes dword the second keeps 1 as a byte

Is there an instruction that keeps 1 as 2 bytes? If no why?