Wigglytuff tend to be chaotic, fun loving, carefree spirits. Their bodies are always reported to be absurdly plush and soft as well. Upon closer study, we found that they simply relax their elastic body upon touch, giving the sensation of infinite give, regardless of how soft or hard the touch itself is. When it comes to the matter of expansion, the more a Wigglytuff inflates themselves, the less voluntary the softness becomes, as some Wigglytuff can become more balloon than Pokemon. For the studies of male specimens, they actually seem to expand their own phallus as well, leading to whatever hole they're filling being completely stuffed to its limit with soft, spongy warmth. Female specimens also seemed to be able to expand their insides, making any male a perfect fit as well, with the added benefit of their internal walls being softer, more sensitive, and more receptive to their own pleasure. Some researchers reported the Wigglytuff they were with actually preferring to expand to a similar height to the one they're mating with, likely a method of encouraging a proper breeding. The result, however, was once the breeding was done, the Wigglytuff could be easily mistaken for body pillows, and with how soft they are, exhaustion quickly put our researchers to sleep. There were more than a few cases of relaxed, drowsy sex, arms wrapped around their Wigglytuff partner, humping away at them until an orgasm puts both parties unconscious