tvastra

tvāṣṭra-mūrtinā — in the form of the son of Tvaṣṭā; SB 6.9.18
tvāṣṭra-bhayāt — from fear of the son of Tvaṣṭā; SB 6.9.23
tvāṣṭra-vadhaḥ — the killing of Vṛtrāsura, the son of Tvaṣṭā; SB 6.13.19-20
tvaṣṭrā — with Tvaṣṭā; SB 8.10.29
tvaṣṭrā — by Tvaṣṭā (Viśvakarmā, the architect of heaven); SB 10.69.7-8
tvaṣṭrā — by Viśvakarmā; SB 10.69.9-12
tvāṣṭra — Vṛtrāsura; SB 11.12.3-6