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HO Puppis (HO Pup) was considered as a Be star candidate due to its γ Cassiopeiae-type light curve, but lacks spectroscopic confirmation. Using distance measured from Gaia Data Release 2 and the spectral energy distribution (SED) fitting on broadband photometry, the Be star nature of HO Pup is ruled out. In contrast, the SED of HO Pup can be fit well with a hot and sub-luminous star or, possibly, a hot subdwarf. Furthermore, based on the 28,700 photometric data points collected from various time-domain surveys and dedicated intensive monitoring observations, the light curves of HO\,Pup resemble well to the IW And-type stars, exhibiting characteristics such as standstill phase, outbursts and dip events. The light curves of HO Pup display various variability time scales, including outbursts cycles range from 23 to 61 days, variations with periods of 3.9 days and 50 minutes during the standstill phase, and a semi-regular ~14 days for the dip events. We have also collected time-series spectra (with various spectral resolutions), at which Balmer emission lines and other expected spectral lines for an IW And-type star were detected, even though some of these lines were also expected to be present on Be stars. Nevertheless, detection of Bowen fluoresces near the outburst phase can be used to discriminate between IW And-type stars and Be stars. Finally, despite only observing for 4 nights, the polarization variation was detected, indicating that HO Pup has intrinsic polarization.