汤马士 is the Hong Kong/Cantonese transliteration of Thomas — Cantonese tong¹-maa⁵-si⁶ matches the English sounds well. The mainland-standard form is
托马斯 (Tuōmǎsī). Best-known bearer in Greater China is 《
汤马士小火车》 (Thomas the Tank Engine).
汤-
马-
士 approximates Tho-ma-s.